workflows/os_comp: Don't run if there aren't relavent changes

.github/workflows/os_comp.yml

@@ -6,7 +6,19 @@ on:
       - master
       # Stable branches such as 0.56 or the eventual 1.0
       - '[0-9]+.[0-9]+'
+    paths:
+      - "mesonbuild/**"
+      - "test cases/**"
+      - ".github/workflows/images.yml"
+      - ".github/workflows/os_comp.yml"
+      - "run_unittests.py"
   pull_request:
+    paths:
+      - "mesonbuild/**"
+      - "test cases/**"
+      - ".github/workflows/images.yml"
+      - ".github/workflows/os_comp.yml"
+      - "run_unittests.py"
 
 jobs:
   arch:
@@ -94,4 +106,4 @@ jobs:
           update-alternatives --set i686-w64-mingw32-gcc   /usr/bin/i686-w64-mingw32-gcc-posix
           update-alternatives --set i686-w64-mingw32-g++   /usr/bin/i686-w64-mingw32-g++-posix
 
-          ./run_tests.py $RUN_TESTS_ARGS -- $MESON_ARGS
+          ./run_tests.py $RUN_TESTS_ARGS -- $MESON_ARGS