ci: right-size five single-core jobs to ubicloud-standard-2

actionlint, skill-docs, version-gate, pr-title-sync, and the evals report
job never exceed one core; standard-8 was ~4x the cost for zero wall-clock.
build-image and the eval matrix keep standard-8.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.github/workflows/actionlint.yml

@@ -15,7 +15,7 @@ concurrency:
 
 jobs:
   actionlint:
-    runs-on: ubicloud-standard-8
+    runs-on: ubicloud-standard-2
     steps:
       - uses: actions/checkout@v4
       # Pull the prebuilt image instead of rhysd/actionlint@v1.7.11 (a Docker

.github/workflows/evals.yml

@@ -294,7 +294,7 @@ jobs:
           retention-days: 90
 
   report:
-    runs-on: ubicloud-standard-8
+    runs-on: ubicloud-standard-2
     needs: evals
     if: always() && github.event_name == 'pull_request' && github.event.pull_request.head.repo.full_name == github.repository
     timeout-minutes: 5

.github/workflows/pr-title-sync.yml

@@ -31,7 +31,7 @@ concurrency:
 jobs:
   sync:
     name: Sync PR title to VERSION
-    runs-on: ubicloud-standard-8
+    runs-on: ubicloud-standard-2
     permissions:
       contents: read
       pull-requests: write

.github/workflows/skill-docs.yml

@@ -15,7 +15,7 @@ concurrency:
 
 jobs:
   check-freshness:
-    runs-on: ubicloud-standard-8
+    runs-on: ubicloud-standard-2
     steps:
       - uses: actions/checkout@v4
       - uses: oven-sh/setup-bun@v2

.github/workflows/version-gate.yml

@@ -14,7 +14,7 @@ concurrency:
 jobs:
   check:
     name: Check VERSION is not stale vs queue
-    runs-on: ubicloud-standard-8
+    runs-on: ubicloud-standard-2
     permissions:
       contents: read
       pull-requests: read