chore: migrate CI workflows to ubuntu-slim for faster startup times (#4007)

*This type of runner is optimized for automation tasks, issue operations
and short-running jobs. They are not suitable for typical heavyweight
CI/CD builds.*
[[1](https://docs.github.com/en/actions/reference/runners/github-hosted-runners#single-cpu-runners)].

We are not necessarily dependent on faster startups, but that seems to
be becoming the best practice now.

Author: KristjanESPERANTO

.github/workflows/automated-tests.yaml

@@ -18,7 +18,7 @@ concurrency:
 
 jobs:
   code-style-check:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     timeout-minutes: 15
     steps:
       - name: "Checkout code"

.github/workflows/dep-review.yaml

@@ -10,7 +10,7 @@ permissions:
 
 jobs:
   dependency-review:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     steps:
       - name: "Checkout code"
         uses: actions/checkout@v6

.github/workflows/electron-rebuild.yaml

@@ -5,7 +5,7 @@ on: [pull_request]
 jobs:
   rebuild:
     name: Run electron-rebuild
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     strategy:
       matrix:
         node-version: [22.21.1, 22.x, 24.x]

.github/workflows/enforce-pullrequest-rules.yaml

@@ -12,7 +12,7 @@ on:
 
 jobs:
   check:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     if: github.event_name == 'pull_request'
     timeout-minutes: 10
     steps:

.github/workflows/release-notes.yaml

@@ -15,7 +15,7 @@ concurrency:
 
 jobs:
   release-notes:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     timeout-minutes: 15
     steps:
       - name: "Checkout code"

.github/workflows/spellcheck.yaml

@@ -12,7 +12,7 @@ permissions:
 
 jobs:
   spellcheck:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     steps:
       - name: Checkout code
         uses: actions/checkout@v6

.github/workflows/stale.yaml

@@ -10,7 +10,7 @@ permissions:
 
 jobs:
   stale:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     steps:
       - uses: actions/stale@v10
         with: