ci: set CFLAGS=-std=gnu11 for linux/musllinux wheels

Cross toolchains in manylinux/musllinux containers default to a pre-C99
gcc dialect, breaking tree-sitter-javascript's scanner.c which declares
loop variables in the for-init.

Author: davidsmfreire

.github/workflows/ci.yml

@@ -43,6 +43,8 @@ jobs:
           python-version: 3.x
       - name: Build wheels
         uses: PyO3/maturin-action@v1
+        env:
+          CFLAGS: "-std=gnu11"
         with:
           working-directory: sqlshield-py
           target: ${{ matrix.platform.target }}
@@ -75,6 +77,8 @@ jobs:
           python-version: 3.x
       - name: Build wheels
         uses: PyO3/maturin-action@v1
+        env:
+          CFLAGS: "-std=gnu11"
         with:
           working-directory: sqlshield-py
           target: ${{ matrix.platform.target }}