Revert "Allow changes to the makefile to rebuild Docker images"

This reverts commit 120e9e2.

Refactoring the `makefile` doesn't need to trigger a rebuild of all images. It was important during a name scheme change, since that was controlled by the `makefile`. Now that the name scheme change has been applied, we no longer need to trigger a build of all images for changes to the `makefile`.

.github/workflows/buildDockerBuildEnv.yml

@@ -37,7 +37,7 @@ jobs:
         id: diff
         run: |
           set +e
-          git diff --exit-code --no-patch "origin/${defaultBranch}" dockerBuildEnv/makefile dockerBuildEnv/nas2d-${{ matrix.platform }}.* ; echo "modified=$?" >> $GITHUB_OUTPUT
+          git diff --exit-code --no-patch "origin/${defaultBranch}" dockerBuildEnv/nas2d-${{ matrix.platform }}.* ; echo "modified=$?" >> $GITHUB_OUTPUT
 
       - name: Docker build
         if: ${{ fromJSON(steps.diff.outputs.modified) }}