Add Discussion label workflow (#11300)

### Motivation and Context

Right now, we need to manually go through each new discussion item to
figure out if it needs certain labels. We also can miss discussion items
as we don't have the "triage" label applied automatically like we do for
issues. We have some discussion categories where users can post for help
-- specifically "General," "Q&A," and "Ideas." Other discussion
categories don't warrant "triage," "python," or ".NET" labels.

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### Description

This PR adds a "Label Discussions" workflow that runs when new
discussions are created as part of General, Ideas, or Q&A, that
leverages GitHub's GraphQL API. This was tested in my SK fork for new
issues, and it properly adds the appropriate label based on the content
of the discussion item.

This should help make sure we don't miss any discussion item as we look
through them during triage.

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### Contribution Checklist

<!-- Before submitting this PR, please make sure: -->

- [X] The code builds clean without any errors or warnings
- [X] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [X] All unit tests pass, and I have added new tests where possible
- [X] I didn't break anyone 😄

Author: moonbox3

.github/workflows/label-discussions.yml

@@ -0,0 +1,107 @@
+name: Label Discussions
+
+on:
+  discussion:
+    types:
+      - created
+
+jobs:
+  label_discussions:
+    runs-on: ubuntu-latest
+    permissions:
+      discussions: write
+    env:
+      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+    steps:
+      - name: Always add "triage" label
+        if: >
+          github.event.discussion.node_id != '' &&
+          (github.event.discussion.category.name == 'General' ||
+           github.event.discussion.category.name == 'Ideas' ||
+           github.event.discussion.category.name == 'Q&A')
+        uses: octokit/[email protected]
+        with:
+          query: |
+            mutation($labelableId: ID!) {
+              addLabelsToLabelable(
+                input: {
+                  labelableId: $labelableId
+                  labelIds: ["LA_kwDOJDJ_Yc8AAAABU2klmQ"]
+                }
+              ) {
+                clientMutationId
+              }
+            }
+          variables: |
+            {
+              "labelableId": "${{ github.event.discussion.node_id }}"
+            }
+
+      - name: Conditionally add "python" label
+        if: >
+          github.event.discussion.node_id != '' &&
+          (github.event.discussion.category.name == 'General' ||
+           github.event.discussion.category.name == 'Ideas' ||
+           github.event.discussion.category.name == 'Q&A') &&
+          (contains(github.event.discussion.body, 'python') ||
+           contains(github.event.discussion.body, 'Python') ||
+           contains(github.event.discussion.title, 'python') ||
+           contains(github.event.discussion.title, 'Python'))
+        uses: octokit/[email protected]
+        with:
+          query: |
+            mutation($labelableId: ID!) {
+              addLabelsToLabelable(
+                input: {
+                  labelableId: $labelableId
+                  labelIds: ["LA_kwDOJDJ_Yc8AAAABO0f2Lg"]
+                }
+              ) {
+                clientMutationId
+              }
+            }
+          variables: |
+            {
+              "labelableId": "${{ github.event.discussion.node_id }}"
+            }
+
+      - name: Conditionally add ".NET" label
+        if: >
+          github.event.discussion.node_id != '' &&
+          (github.event.discussion.category.name == 'General' ||
+           github.event.discussion.category.name == 'Ideas' ||
+           github.event.discussion.category.name == 'Q&A') &&
+          (contains(github.event.discussion.body, '.net') ||
+           contains(github.event.discussion.body, '.NET') ||
+           contains(github.event.discussion.title, '.net') ||
+           contains(github.event.discussion.title, '.NET') ||
+           contains(github.event.discussion.body, 'dotnet') ||
+           contains(github.event.discussion.body, 'DotNet') ||
+           contains(github.event.discussion.title, 'dotnet') ||
+           contains(github.event.discussion.title, 'DotNet') ||
+           contains(github.event.discussion.body, 'c#') ||
+           contains(github.event.discussion.body, 'C#') ||
+           contains(github.event.discussion.title, 'c#') ||
+           contains(github.event.discussion.title, 'C#') ||
+           contains(github.event.discussion.body, 'csharp') ||
+           contains(github.event.discussion.body, 'CSharp') ||
+           contains(github.event.discussion.title, 'csharp') ||
+           contains(github.event.discussion.title, 'CSharp'))
+        uses: octokit/[email protected]
+        with:
+          query: |
+            mutation($labelableId: ID!) {
+              addLabelsToLabelable(
+                input: {
+                  labelableId: $labelableId
+                  labelIds: ["LA_kwDOJDJ_Yc8AAAABN_r7Lw"]
+                }
+              ) {
+                clientMutationId
+              }
+            }
+          variables: |
+            {
+              "labelableId": "${{ github.event.discussion.node_id }}"
+            }