CI: Switch over some workflows to Blacksmith.sh runners

The people over at Blacksmith.sh have generously offered usage of their
runners for our organization, so let's try to switch over some simple
workflows. The runners should be drop-in replacements.

.github/workflows/lint-commits.yml

@@ -7,7 +7,7 @@ on: [pull_request_target]
 
 jobs:
   lint:
-    runs-on: ubuntu-24.04
+    runs-on: blacksmith-2vcpu-ubuntu-2404
     if: github.repository == 'LadybirdBrowser/ladybird'
 
     steps:

.github/workflows/merge-conflict-labeler.yml

@@ -12,7 +12,7 @@ on:
 
 jobs:
   auto-labeler:
-    runs-on: ubuntu-24.04
+    runs-on: blacksmith-2vcpu-ubuntu-2404
     permissions:
       contents: read
       pull-requests: write

.github/workflows/notes-push.yml

@@ -5,10 +5,11 @@ on:
       - master
 permissions:
   contents: write
+
 jobs:
   build:
     if: github.repository == 'LadybirdBrowser/ladybird'
-    runs-on: ubuntu-latest
+    runs-on: blacksmith-2vcpu-ubuntu-2404
     steps:
       - uses: actions/checkout@v4
         with:

.github/workflows/stale.yml

@@ -9,7 +9,7 @@ on:
 
 jobs:
   stale:
-    runs-on: ubuntu-24.04
+    runs-on: blacksmith-2vcpu-ubuntu-2404
     permissions:
       actions: write  # required for cache management (see https://github.com/actions/stale/issues/1133)
       pull-requests: write