use smaller machines in CI PR runs

Author: klensy

.github/workflows/ci.yml

@@ -50,10 +50,10 @@ jobs:
       matrix:
         include:
           - name: mingw-check
-            os: ubuntu-20.04-16core-64gb
+            os: ubuntu-20.04-4core-16gb
             env: {}
           - name: mingw-check-tidy
-            os: ubuntu-20.04-16core-64gb
+            os: ubuntu-20.04-4core-16gb
             env: {}
           - name: x86_64-gnu-llvm-15
             os: ubuntu-20.04-16core-64gb

src/ci/github-actions/ci.yml

@@ -318,10 +318,10 @@ jobs:
       matrix:
         include:
           - name: mingw-check
-            <<: *job-linux-16c
+            <<: *job-linux-4c
 
           - name: mingw-check-tidy
-            <<: *job-linux-16c
+            <<: *job-linux-4c
 
           - name: x86_64-gnu-llvm-15
             <<: *job-linux-16c