revert forced usage of bash, instead opt for (more) explicit compiler selection.

.github/workflows/ci.yaml

@@ -14,6 +14,14 @@ jobs:
           - windows-latest
           - windows-11-arm
           # - macos-latest
+        cc:
+          - cc
+          - cc
+          - gcc
+          - gcc
+          - cc
+    env:
+        CC: ${{matrix.cc}}
     runs-on: ${{matrix.os}}
     steps:
       - uses: actions/checkout@v5

Makefile

@@ -1,6 +1,5 @@
 # Copyright (c) 2025 Quinn
 # Licensed under the MIT Licence. See LICENSE for details
-SHELL = bash
 
 # build configuration, information about the current build process
 NAME    = mcaselector-lite