ci: use aws codebuild for linux 16 core runners

Author: marcoieni

src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile

@@ -2,7 +2,7 @@
 # CentOS 7 has headers for kernel 3.10, but that's fine as long as we don't
 # actually use newer APIs in rustc or std without a fallback. It's more
 # important that we match glibc for ELF symbol versioning.
-FROM centos:7
+FROM ghcr.io/rust-lang/centos:7
 
 WORKDIR /build
 

src/ci/github-actions/jobs.yml

@@ -118,9 +118,9 @@ pr:
     env:
       ENABLE_GCC_CODEGEN: "1"
       DOCKER_SCRIPT: x86_64-gnu-llvm.sh
-    <<: *job-linux-16c
+    <<: *job-linux-36c-codebuild
   - name: x86_64-gnu-tools
-    <<: *job-linux-16c
+    <<: *job-linux-36c-codebuild
 
 # Jobs that run when you perform a try build (@bors try)
 # These jobs automatically inherit envs.try, to avoid repeating
@@ -213,13 +213,13 @@ auto:
   - name: dist-x86_64-linux
     env:
       CODEGEN_BACKENDS: llvm,cranelift
-    <<: *job-linux-16c
+    <<: *job-linux-36c-codebuild
 
   - name: dist-x86_64-linux-alt
     env:
       IMAGE: dist-x86_64-linux
       CODEGEN_BACKENDS: llvm,cranelift
-    <<: *job-linux-16c
+    <<: *job-linux-36c-codebuild
 
   - name: dist-x86_64-musl
     env: