Add uvx test case to CI

Author: zanieb

.github/workflows/ci.yml

@@ -203,8 +203,10 @@ jobs:
       - name: "Smoke test"
         run: |
           uv="./target/debug/uv"
+          uvx="./target/debug/uvx"
           $uv venv -v
           $uv pip install ruff -v
+          $uvx -v ruff --version
 
       - name: "Smoke test completion"
         run: |
@@ -248,8 +250,10 @@ jobs:
       - name: "Smoke test"
         run: |
           uv="./target/debug/uv"
+          uvx="./target/debug/uvx"
           $uv venv -v
           $uv pip install ruff -v
+          $uvx -v ruff --version
 
   cargo-test-windows:
     timeout-minutes: 15
@@ -298,8 +302,10 @@ jobs:
         working-directory: ${{ env.UV_WORKSPACE }}
         run: |
           Set-Alias -Name uv -Value ./target/debug/uv
+          Set-Alias -Name uvx -Value ./target/debug/uvx
           uv venv -v
           uv pip install ruff -v
+          uvx -v ruff --version
 
       - name: "Smoke test completion"
         working-directory: ${{ env.UV_WORKSPACE }}