Bump softprops/action-gh-release from 0.1.5 to 0.1.15 (#317)

Bumps [softprops/action-gh-release](https://github.com/softprops/action-gh-release) from 0.1.5 to 0.1.15.
- [Release notes](https://github.com/softprops/action-gh-release/releases)
- [Changelog](https://github.com/softprops/action-gh-release/blob/master/CHANGELOG.md)
- [Commits](b7e450da2a...de2c0eb89a)

---
updated-dependencies:
- dependency-name: softprops/action-gh-release
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/github-release.yml

@@ -24,7 +24,7 @@ jobs:
           mkdir -p dist
           cp -r build synapse-admin-$version
           tar chvzf dist/synapse-admin-$version.tar.gz synapse-admin-$version
-      - uses: softprops/action-gh-release@b7e450da2a4b4cb4bfbae528f788167786cfcedf
+      - uses: softprops/action-gh-release@de2c0eb89ae2a093876385947365aca7b0e5f844
         with:
           files: dist/*.tar.gz
         env: