Explicitely set use_static_cpp=yes on Linux

That option used to default to True for better portability, but is now
False since godotengine/godot-cpp#1876, and it appears to cause problems
when users have a different version of libstdc++ on their distro than the
one used on the Ubuntu VM of Github Actions

Author: Zylann

.github/workflows/extension_builds.yml

@@ -107,7 +107,7 @@ jobs:
         env:
           SCONS_CACHE: ${{ github.workspace }}/.scons-cache/
         run: |
-          scons target=${{ matrix.target-type }} platform=${{ matrix.target.platform }} arch=${{ matrix.target.arch }} precision=${{ matrix.float-precision }} dev_build=no verbose=yes
+          scons target=${{ matrix.target-type }} platform=${{ matrix.target.platform }} arch=${{ matrix.target.arch }} precision=${{ matrix.float-precision }} dev_build=no verbose=yes use_static_cpp=yes
 
       # Sign the binary (macOS only)
       # - name: Mac Sign