github/workflows: Bump microsoft/setup-msbuild from 2 to 3.

Bumps [microsoft/setup-msbuild](https://github.com/microsoft/setup-msbuild) from 2 to 3.
- [Release notes](https://github.com/microsoft/setup-msbuild/releases)
- [Commits](microsoft/setup-msbuild@v2...v3)

---
updated-dependencies:
- dependency-name: microsoft/setup-msbuild
  dependency-version: '3'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/ports_windows.yml

@@ -52,7 +52,7 @@ jobs:
       uses: actions/setup-python@v6
       with:
         python-version: '3.11'
-    - uses: microsoft/setup-msbuild@v2
+    - uses: microsoft/setup-msbuild@v3
       with:
         vs-version: ${{ matrix.vs_version }}
     - uses: actions/checkout@v6