only run n i x on push events and if the word is in the commit message

Author: yforster

.github/workflows/nix-action-coq-8.16-macos.yml

@@ -1,6 +1,7 @@
 jobs:
   coq:
     needs: []
+    if: ${{ contains(github.event.head_commit.message, 'nix') }}
     runs-on: macos-latest
     concurrency:
       group: ${{ github.workflow }}-MacOS-coq-${{ github.event_name }}-${{ github.head_ref || github.run_id }}
@@ -173,14 +174,8 @@ jobs:
         --argstr job "metacoq"
 name: Nix CI for bundle coq-8.16
 'on':
-  pull_request:
-    paths:
-    - .github/workflows/**
   pull_request_target:
-    types:
-    - opened
-    - synchronize
-    - reopened
+    types: []
   push:
     branches:
     - master

.github/workflows/nix-action-coq-8.16-ubuntu.yml

@@ -1,6 +1,7 @@
 jobs:
   coq:
     needs: []
+    if: ${{ contains(github.event.head_commit.message, 'nix') }}
     runs-on: ubuntu-latest
     concurrency:
       group: ${{ github.workflow }}-Ubuntu-coq-${{ github.event_name }}-${{ github.head_ref || github.run_id }}
@@ -173,14 +174,8 @@ jobs:
         --argstr job "metacoq"
 name: Nix CI for bundle coq-8.16
 'on':
-  pull_request:
-    paths:
-    - .github/workflows/**
   pull_request_target:
-    types:
-    - opened
-    - synchronize
-    - reopened
+    types: []
   push:
     branches:
     - master