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.

.github/workflows/tests.yml

@@ -479,8 +479,12 @@ jobs:
           name: binaries
           path: binaries
 
-  upload_release:
+  # Given the clearly documented use of annotated tags to signal releases,
-    name: Upload Release Assets
+  # 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.
+  #
+  get_tagtype:
+    name: Get the type of Tag
     if: startsWith(github.ref, 'refs/tags/')
     needs:
       - package_dpkg
@@ -491,6 +495,18 @@ jobs:
       - binaries_linux_crosscompile
     runs-on: ubuntu-latest
 
+    steps:
+      - name: Set variable
+        run: |
+          echo '::set-output name=TAGTYPE::$(git cat-file -t $GITHUB_REF)'
+
+  upload_release:
+    name: Upload Release Assets
+    if: steps.get_tagtype.outputs.TAGTYPE == 'tag'
+    needs:
+      - get_tagtype
+    runs-on: ubuntu-latest
+
     steps:
       - name: Fetch all Artifacts
         uses: actions/download-artifact@v2