chore: Update GitHub workflows to install .NET 8

Author: jskeet

.github/workflows/bigtable-conformance.yml

@@ -35,7 +35,9 @@ jobs:
         path: cloud-bigtable-clients-test
     - uses: actions/setup-dotnet@v4
       with:
-        dotnet-version: 6.0.x
+        dotnet-version: |
+          6.0.x
+          8.0.x
     - uses: actions/setup-go@v5
       with:
         go-version: '>=1.20.2'

.github/workflows/build-pr.yml

@@ -18,10 +18,12 @@ jobs:
         submodules: true
         fetch-depth: 100
 
-    - name: Setup .NET 6.0
-      uses: actions/setup-dotnet@v4
+    - name: Setup .NET
+    - uses: actions/setup-dotnet@v4
       with:
-        dotnet-version: 6.0.x
+        dotnet-version: |
+          6.0.x
+          8.0.x
 
     # The GitHub checkout action leaves the repo in a slightly awkward
     # state. This tidies it up.

.github/workflows/build-push.yml

@@ -17,10 +17,12 @@ jobs:
       with:
         submodules: true
 
-    - name: Setup .NET 6.0
-      uses: actions/setup-dotnet@v4
+    - name: Setup .NET
+    - uses: actions/setup-dotnet@v4
       with:
-        dotnet-version: 6.0.x
+        dotnet-version: |
+          6.0.x
+          8.0.x
 
     - name: Build and test
       run: |

.github/workflows/diff-pr.yml

@@ -27,10 +27,12 @@ jobs:
         git checkout -b main ${{ github.event.pull_request.base.sha }}
         git checkout pr-head
 
-    - name: Setup .NET 6.0
-      uses: actions/setup-dotnet@v4
+    - name: Setup .NET
+    - uses: actions/setup-dotnet@v4
       with:
-        dotnet-version: 6.0.x
+        dotnet-version: |
+          6.0.x
+          8.0.x
 
     - name: Detect PR changes
       env:

.github/workflows/spanner-emulator-pr-push.yml

@@ -27,11 +27,12 @@ jobs:
       with:
         submodules: true
 
-    # Install .NET 6 for building
-    - name: Setup .NET 6.0
-      uses: actions/setup-dotnet@v4
+    - name: Setup .NET
+    - uses: actions/setup-dotnet@v4
       with:
-        dotnet-version: 6.0.x
+        dotnet-version: |
+          6.0.x
+          8.0.x
 
     - name: Spanner Emulator
       env:

.github/workflows/storage-retry-conformance.yml

@@ -28,10 +28,12 @@ jobs:
       with:
         submodules: true
 
-    - name: Setup .NET 6.0
-      uses: actions/setup-dotnet@v4
+    - name: Setup .NET
+    - uses: actions/setup-dotnet@v4
       with:
-        dotnet-version: 6.0.x
+        dotnet-version: |
+          6.0.x
+          8.0.x
 
     - run: dotnet test Google.Cloud.Storage.V1.RetryConformanceTests.csproj
       env: