Add path filter to test workflow

Only run tests on pull requests that change files relevant to the
build, setup, report, or test logic. Manual dispatch is unaffected.

Author: dash14

.github/workflows/test.yml

@@ -7,6 +7,15 @@ on:
   pull_request:
     branches:
       - main
+    paths:
+      - 'docker/**'
+      - 'setup/**'
+      - 'report/**'
+      - 'test/**'
+      - 'compose.yml'
+      - 'compose.test.yml'
+      - 'Makefile'
+      - '.github/workflows/test.yml'
 
 jobs:
   unit_test: