Bump scitools/workflows from 2023.06.0 to 2023.09.0 (#306)

Bumps [scitools/workflows](https://github.com/scitools/workflows) from 2023.06.0 to 2023.09.0.
- [Release notes](https://github.com/scitools/workflows/releases)
- [Commits](SciTools/workflows@2023.06.0...2023.09.0)

---
updated-dependencies:
- dependency-name: scitools/workflows
  dependency-type: direct:production
...

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

.github/workflows/ci-manifest.yml

@@ -20,4 +20,4 @@ concurrency:
 jobs:
   manifest:
     name: "check-manifest"
-    uses: scitools/workflows/.github/workflows/ci-manifest.yml@2023.06.0
+    uses: scitools/workflows/.github/workflows/ci-manifest.yml@2023.09.0