ci(workflow): add XAI_API_KEY env to tests and switch lint/build to ubuntu-gitea runner

- Inject XAI_API_KEY from secrets for test execution.
- Update lint and build jobs to run on ubuntu-gitea instead of ubuntu-latest.

.gitea/workflows/ci.yml

@@ -31,7 +31,10 @@ jobs:
         run: go mod download
 
       - name: Run tests
-        run: go test -v -race -coverprofile=coverage.out ./...
+        env:
+          XAI_API_KEY: ${{ secrets.XAI_API_KEY }}
+        run: | 
+            go test -v -race -coverprofile=coverage.out ./...
 
       - name: Upload coverage
         uses: codecov/codecov-action@v4
@@ -41,7 +44,7 @@ jobs:
 
   lint:
     name: Lint
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-gitea
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
@@ -58,7 +61,7 @@ jobs:
 
   build:
     name: Build
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-gitea
     steps:
       - name: Checkout code
         uses: actions/checkout@v4