Add a way to provide custom overrides to the test run action

.github/workflows/run_tests.yml

@@ -50,6 +50,11 @@ on:
  description: "Which GMod branch to run your tests on. Must be: 'live' or 'x86-64'"
  default: "live"
 
+ custom-overrides:
+ type: string
+ required: false
+ description: "An absolute path with custom files to copy to the server directly. Structure should match the contents of `garrysmod/`"
+
 jobs:
  test:
  name: "Run tests"
@@ -118,6 +123,11 @@ jobs:
  mkdir --verbose --parents "$dest"
  cp --recursive --verbose $source/* "$dest/"
 
+ - name: Sync custom overrides
+ if: ${{ inputs.custom-overrides }}
+ run: |
+ rsync --verbose --archive ${{ inputs.custom-overrides }} $GITHUB_WORKSPACE/garrysmod_override/
+
  - name: Pull GLuaTest Runner
  env:
  REQUIREMENTS: "${{ github.workspace }}/project/${{ inputs.requirements }}"