use gcc not clang

Author: mattip

.github/workflows/posix.yml

@@ -99,9 +99,9 @@ jobs:
         brew reinstall gcc
         brew install coreutils
         brew install llvm
-        ls /usr/local/Cellar/llvm
-        echo "/usr/local/opt/llvm/bin" >>$GITHUB_PATH
-        echo "CC=/usr/local/opt/llvm/bin/clang" >> $GITHUB_ENV;
+        ls /usr/local/Cellar/gcc
+        echo "/usr/local/Cellar/gcc/14.2.0_1/bin" >>$GITHUB_PATH
+        echo "CC=/usr/local/Cellar/gcc/14.2.0_1/bin/gcc-14" >> $GITHUB_ENV;
         echo "RANLIB=/usr/bin/ranlib" >> $GITHUB_ENV;