Only run GH actions when relevant files were changed

.github/workflows/json_schema.yml

@@ -4,9 +4,13 @@ on:
   push:
     branches:
       - main
+    paths:
+      - '**.json'
   pull_request:
     branches:
       - main
+    paths:
+      - '**.json'
 
 jobs:
   validate:

.github/workflows/nix.yml

@@ -1,7 +1,11 @@
 name: "Nix Flake Check"
 on:
   pull_request:
+    paths:
+      - '**.nix'
   push:
+    paths:
+      - '**.nix'
 jobs:
   tests:
     runs-on: ubuntu-latest

.github/workflows/shellcheck.yml

@@ -4,9 +4,13 @@ on:
   push:
     branches:
       - main
+    paths:
+      - '**.sh'
   pull_request:
     branches:
       - main
+    paths:
+      - '**.sh'
 
 jobs:
   shellcheck: