Add test on push for token only auth (#16)

Covers a missing testcase of push with a token but without providing a
username for login. Checks credentials are still passed.

.github/workflows/ci.yaml

@@ -177,10 +177,33 @@ jobs:
           push: true
           archive: false
           comment: false
+  push-token-only:
+    needs: build
+    runs-on: ubuntu-latest
+    if: ${{ github.event_name == 'push' }} # --git-metadata is only available on push
+    steps:
+      - uses: actions/checkout@v4
+      - env:
+          BUF_USERNAME: ${{ secrets.BUF_USERNAME }}
+        run: |
+          mkdir -p proto/foo/v1
+          printf "version: v2\nmodules:\n  - path: proto\n    name: buf.build/${BUF_USERNAME}/foo\n" > buf.yaml
+          printf "syntax = \"proto3\";\npackage foo.v1;\nmessage Bar {}\n" > proto/foo/v1/bar.proto
+      - uses: ./
+        with:
+          token: ${{ secrets.BUF_TOKEN }}
+          lint: false
+          format: false
+          breaking: false
+          push: true
+          archive: false
+          comment: false
   archive:
     if: github.event_name == 'push' && github.ref_name != github.event.repository.default_branch
     runs-on: ubuntu-latest
-    needs: push
+    needs:
+      - push
+      - push-token-only
     steps:
       - uses: actions/checkout@v4
       - env:
@@ -201,10 +224,12 @@ jobs:
           # On push github.ref_name, on delete github.event.ref_name.
           archive_labels: ${{ github.ref_name }}
           comment: false
-  archive_not_exists:
+  archive-not-exists:
     if: github.event_name == 'push'
     runs-on: ubuntu-latest
-    needs: push
+    needs:
+      - push
+      - push-token-only
     steps:
       - uses: actions/checkout@v4
       - env: