chore: sync met 'BRP-API/brp-shared-dotnet' repo

Signed-off-by: MelvLee <[email protected]>

Author: MelvLee

.github/actions/valideer-dotnet-solution/action.yml

@@ -14,6 +14,7 @@ runs:
       with:
         dotnet-version: |
           6.0.x
+          7.0.x
           8.0.x
     - name: Restore dependencies
       run: dotnet restore ${{ inputs.path-solution-file }}