fix: use workspace path in check-codegen workflow

Signed-off-by: Seth Nickell <snickell@gmail.com>

Author: snickell

.github/workflows/ci.yaml

@@ -216,11 +216,11 @@ jobs:
     - name: Git stuff
       # As of go 1.20, this seems to be necessary for invoking git commands
       # within the container
-      run: git config --global --add safe.directory /__w/kargo/kargo
+      run: git config --global --add safe.directory "$GITHUB_WORKSPACE"
     - name: Run Codegen
       run: make codegen
     - name: Check nothing has changed
-      run: git diff --exit-code -- .
+      run: git -C "$GITHUB_WORKSPACE" diff --exit-code -- .
 
   build-image:
     needs: [test-unit, lint-go, lint-charts, lint-proto, lint-and-typecheck-ui, check-codegen]