Use the latest MSVS earlier than 14.38 for Qt5

Because MSVC 14.38 has many issues with Qt5, and 14.29 is now the
next-latest MSVC on GitHub hosted runners (win22 20240304.2.1).

https://github.com/actions/runner-images/blob/main/images/windows/Windows2022-Readme.md

.github/workflows/build.yaml

@@ -367,7 +367,7 @@ jobs:
       uses: ilammy/msvc-dev-cmd@v1
       with:
         arch: ${{ matrix.msvcArch }}
-        #toolset: ${{ startsWith(matrix.qt, '5') && '14.37' || '' }} # MSVC 14.38+ has many deprecation issues with Qt5.
+        toolset: ${{ startsWith(matrix.qt, '5') && '14.29' || '' }} # MSVC 14.38+ has many deprecation issues with Qt5.
     - name: Build
       env:
         PROJECT_BUILD_ID: ${{ github.run_number }}.win.${{ matrix.arch }}.${{ matrix.tool }}.qt-${{ matrix.qt }}