Bump actions/setup-dotnet from 4 to 5 (#8485)

Bumps [actions/setup-dotnet](https://github.com/actions/setup-dotnet) from 4 to 5.
- [Release notes](https://github.com/actions/setup-dotnet/releases)
- [Commits](https://github.com/actions/setup-dotnet/compare/v4...v5)

---
updated-dependencies:
- dependency-name: actions/setup-dotnet
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/nightly-validation.yml

@@ -30,7 +30,7 @@ jobs:
         uses: actions/checkout@v6
       
       - name: Setup .NET
-        uses: actions/setup-dotnet@v4
+        uses: actions/setup-dotnet@v5
         with:
           dotnet-version: '8.x'
       
@@ -90,7 +90,7 @@ jobs:
         uses: actions/checkout@v6
       
       - name: Setup .NET
-        uses: actions/setup-dotnet@v4
+        uses: actions/setup-dotnet@v5
         with:
           dotnet-version: '8.x'
       
@@ -145,7 +145,7 @@ jobs:
         uses: actions/checkout@v6
       
       - name: Setup .NET
-        uses: actions/setup-dotnet@v4
+        uses: actions/setup-dotnet@v5
         with:
           dotnet-version: '8.x'
       
@@ -200,7 +200,7 @@ jobs:
         uses: actions/checkout@v6
       
       - name: Setup .NET
-        uses: actions/setup-dotnet@v4
+        uses: actions/setup-dotnet@v5
         with:
           dotnet-version: '8.x'