Actions: shorten timeout and enable cancel-in-progress (#3151)

This should free up resources (even if we're not paying for them) and
maybe make our builds run a little bit faster / trigger a little sooner.

Author: kainino0x

.github/workflows/pr.yml

@@ -4,9 +4,14 @@ on:
   pull_request:
     branches: [main]
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.ref }}
+  cancel-in-progress: true
+
 jobs:
   build:
     runs-on: ubuntu-latest
+    timeout-minutes: 15
     steps:
       - uses: actions/checkout@v3
         with:

.github/workflows/push.yml

@@ -4,9 +4,14 @@ on:
   push:
     branches: [main]
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.ref }}
+  cancel-in-progress: true
+
 jobs:
   build:
     runs-on: ubuntu-latest
+    timeout-minutes: 15
     steps:
       - uses: actions/[email protected]
         with: