[main] (deps): Bump dotnet/arcade/.github/workflows/backport-base.yml (#65487)

Bumps [dotnet/arcade/.github/workflows/backport-base.yml](https://github.com/dotnet/arcade) from ab22aeec12730f321addeb11568f0213b23ac3f4 to 973af93a9b8380170914c7b91e0d5143a20640ab.
- [Commits](https://github.com/dotnet/arcade/compare/ab22aeec12730f321addeb11568f0213b23ac3f4...973af93a9b8380170914c7b91e0d5143a20640ab)

---
updated-dependencies:
- dependency-name: dotnet/arcade/.github/workflows/backport-base.yml
  dependency-version: 973af93a9b8380170914c7b91e0d5143a20640ab
  dependency-type: direct:production
...

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

.github/workflows/backport.yml

@@ -14,7 +14,7 @@ permissions:
 
 jobs:
   backport:
-    uses: dotnet/arcade/.github/workflows/backport-base.yml@ab22aeec12730f321addeb11568f0213b23ac3f4 # 2025-01-13
+    uses: dotnet/arcade/.github/workflows/backport-base.yml@973af93a9b8380170914c7b91e0d5143a20640ab # 2025-01-13
     with:
       pr_description_template: |
         Backport of #%source_pr_number% to %target_branch%