Bump martincostello/update-dotnet-sdk from 3.5.0 to 3.8.1 (#1038)

Bumps [martincostello/update-dotnet-sdk](https://github.com/martincostello/update-dotnet-sdk) from 3.5.0 to 3.8.1.
- [Release notes](https://github.com/martincostello/update-dotnet-sdk/releases)
- [Commits](martincostello/update-dotnet-sdk@548112d...e7501eb)

---
updated-dependencies:
- dependency-name: martincostello/update-dotnet-sdk
  dependency-version: 3.8.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

.github/workflows/update-dotnet-sdk.yml

@@ -9,7 +9,7 @@ permissions: {}
 
 jobs:
   update-sdk:
-    uses: martincostello/update-dotnet-sdk/.github/workflows/update-dotnet-sdk.yml@548112dca44d56d69830fce804a007788db3d158 # v3.5.0
+    uses: martincostello/update-dotnet-sdk/.github/workflows/update-dotnet-sdk.yml@e7501ebba8948a456d25ac2ff867af8c8f680454 # v3.8.1
     permissions:
       contents: read
     with: