CI: fix MSVC builds when building dependencies

Author: triplef

.github/workflows/main.yml

@@ -232,10 +232,12 @@ jobs:
           # make Windows packages like Clang available in MSYS
           path-type: inherit
 
-      - name: Delete MinGW gmake (MSVC)
-        if: env.IS_WINDOWS_MSVC == 'true'
-        # delete /c/Strawberry/c/bin/gmake built for MinGW that is found on runners, because we must use make built for MSYS
-        run: if GMAKE_PATH=`which gmake`; then rm -f "$GMAKE_PATH"; fi
+      - name: Remove Perl Strawberry installation (MSVC)
+        if: env.IS_WINDOWS_MSVC == 'true' && github.event.inputs.tools_windows_msvc_branch
+        # this directory contains various MinGW libraries that can get picked up by CMake
+        # and a MinGW gmake that we cannot use (we must use MSYS make), so we delete it
+        run: rmdir /S /Q C:\Strawberry\c
+        shell: cmd
 
       - name: Install Windows packages (MSVC)
         if: env.IS_WINDOWS_MSVC == 'true'