Only trigger automatic release process on annotated tags (#881)

* Only trigger release process on annotated tags

Annotated tags are meant for releases while lightweight tags are meant
for private or temporary object labels.

For this reason, we should not trigger the automatic release actions
unless we have an annotated tag.

* Actions set-output is only scoped within the same job id

* Fix workflow syntax - of course keys cannot be defined twice

.github/workflows/tests.yml

@@ -479,6 +479,10 @@ jobs:
           name: binaries
           path: binaries
 
+  # Given the clearly documented use of annotated tags to signal releases,
+  # it seems strange that there is no simple way to trigger actions if the
+  # tag is annotated.  So we need to jump through some hoops.
+  #
   upload_release:
     name: Upload Release Assets
     if: startsWith(github.ref, 'refs/tags/')
@@ -492,12 +496,18 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
+      - name: Get Tag Type
+        run: |
+          echo '::set-output name=TAGTYPE::$(git cat-file -t $GITHUB_REF)'
+
       - name: Fetch all Artifacts
+        if: steps.get_tagtype.outputs.TAGTYPE == 'tag'
         uses: actions/download-artifact@v2
         with:
           path: artifacts
 
       - name: Upload Assets to Release
+        if: steps.get_tagtype.outputs.TAGTYPE == 'tag'
         uses: softprops/action-gh-release@v1
         with:
           prerelease: true