Remove / from tag names

This broke the publish step for all pull request started workflows.
Because this tag is used for both creating a directory and creating a
tar file.

.github/workflows/release.yml

@@ -265,7 +265,8 @@ jobs:
               if [[ $platform =~ "windows" ]]; then
                   exe=".exe"
               fi
-              pkgname=helix-$GITHUB_REF_NAME-$platform
+              tag=${GITHUB_REF_NAME//\//}
+              pkgname=helix-$tag-$platform
               mkdir -p $pkgname
               cp $source/LICENSE $source/README.md $pkgname
               mkdir $pkgname/contrib