Bump mymindstorm/setup-emsdk from 14 to 15

Bumps [mymindstorm/setup-emsdk](https://github.com/mymindstorm/setup-emsdk) from 14 to 15.
- [Release notes](https://github.com/mymindstorm/setup-emsdk/releases)
- [Commits](emscripten-core/setup-emsdk@v14...v15)

---
updated-dependencies:
- dependency-name: mymindstorm/setup-emsdk
  dependency-version: '15'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/build.yml

@@ -71,7 +71,7 @@ jobs:
     # Setup Emsdk
     - name: Setup emscripten
       if: ${{ matrix.confs.plat == 'wasm' }}
-      uses: mymindstorm/setup-emsdk@v14
+      uses: mymindstorm/setup-emsdk@v15
       with:
         version: 4.0.15
         actions-cache-folder: emsdk-cache-${{ matrix.confs.mode }}