Slim CI matrix for PRs to ubuntu-latest / r-release only

For pull requests, check-recent now runs a single job (ubuntu-latest,
r-release) via a setup job that emits the matrix as JSON. On push and
schedule the full matrix is unchanged (devel + release on all OSes,
oldrel-1 through oldrel-4).

Also removed the pull_request trigger from check-recent-dev-pkgs; the
dev-packages check only needs to run on push/schedule.

https://claude.ai/code/session_01XHWLohiSTdZvCutwD7ag2b

.github/workflows/check-current-testthat-dev-versions.yaml

@@ -28,9 +28,6 @@
 # ==================================================================== #
 
 on:
-  pull_request:
-    # run in each PR in this repo
-    branches: '**'
   push:
     branches: '**'
   schedule:

.github/workflows/check-current-testthat.yaml

@@ -41,7 +41,22 @@ on:
 name: check-recent
 
 jobs:
+  setup:
+    runs-on: ubuntu-latest
+    outputs:
+      matrix: ${{ steps.set-matrix.outputs.matrix }}
+    steps:
+      - id: set-matrix
+        shell: bash
+        run: |
+          if [ "${{ github.event_name }}" = "pull_request" ]; then
+            echo 'matrix={"config":[{"os":"ubuntu-latest","r":"release","allowfail":false}]}' >> "$GITHUB_OUTPUT"
+          else
+            echo 'matrix={"config":[{"os":"windows-latest","r":"devel","allowfail":false},{"os":"ubuntu-latest","r":"devel","allowfail":false,"http-user-agent":"release"},{"os":"macOS-latest","r":"release","allowfail":true},{"os":"windows-latest","r":"release","allowfail":false},{"os":"ubuntu-latest","r":"release","allowfail":false},{"os":"ubuntu-latest","r":"oldrel-1","allowfail":false},{"os":"ubuntu-latest","r":"oldrel-2","allowfail":false},{"os":"ubuntu-latest","r":"oldrel-3","allowfail":false},{"os":"ubuntu-latest","r":"oldrel-4","allowfail":false}]}' >> "$GITHUB_OUTPUT"
+          fi
+
   R-code-check:
+    needs: setup
     runs-on: ${{ matrix.config.os }}
 
     continue-on-error: ${{ matrix.config.allowfail }}
@@ -50,23 +65,7 @@ jobs:
 
     strategy:
       fail-fast: false
-      matrix:
+      matrix: ${{ fromJSON(needs.setup.outputs.matrix) }}
-        config:
-          # current development version, check all major OSes:
-          # - {os: macOS-latest,   r: 'devel', allowfail: true}
-          - {os: windows-latest, r: 'devel', allowfail: false}
-          - {os: ubuntu-latest,  r: 'devel', allowfail: false, http-user-agent: 'release'}
-
-          # current 'release' version, check all major OSes:
-          - {os: macOS-latest,   r: 'release', allowfail: true}
-          - {os: windows-latest, r: 'release', allowfail: false}
-          - {os: ubuntu-latest,  r: 'release', allowfail: false}
-
-          # older versions (see also check-old-tinytest.yaml for even older versions):
-          - {os: ubuntu-latest, r: 'oldrel-1', allowfail: false}
-          - {os: ubuntu-latest, r: 'oldrel-2', allowfail: false}
-          - {os: ubuntu-latest, r: 'oldrel-3', allowfail: false}
-          - {os: ubuntu-latest, r: 'oldrel-4', allowfail: false}
 
     env:
       GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}