Move CI auditing into separate workflow (#485)

Separate the continuous audit job from the general checks workflow. The
motivation for this is that checks should always pass (similar to `npm
run verify`), but audit may not always be passing and this is not
always a problem.

.github/workflows/audit.yml

@@ -0,0 +1,14 @@
+name: Audit
+on:
+  pull_request: ~
+  push:
+    branches:
+      - main
+      - v2
+
+permissions: read-all
+
+jobs:
+  audit:
+    name: Audit
+    uses: ericcornelissen/eslint-plugin-top/.github/workflows/reusable-audit.yml@main

.github/workflows/check.yml

@@ -11,9 +11,6 @@ on:
 permissions: read-all
 
 jobs:
-  audit:
-    name: Audit
-    uses: ericcornelissen/eslint-plugin-top/.github/workflows/reusable-audit.yml@main
   build:
     name: Build
     runs-on: ubuntu-22.04