Extract common macOS x86_64 target environment

Author: shepmaster

src/ci/github-actions/jobs.yml

@@ -94,6 +94,12 @@ envs:
     SELECT_XCODE: /Applications/Xcode_15.4.app
     USE_XCODE_CLANG: 1
 
+  # Ensure that host tooling is tested on our minimum supported macOS
+  # version.
+  env-macos-x86_64-target: &env-macos-x86_64-target
+    MACOSX_DEPLOYMENT_TARGET: 10.12
+    MACOSX_STD_DEPLOYMENT_TARGET: 10.12
+
 jobs:
   dist-x86_64-linux: &job-dist-x86_64-linux
     name: dist-x86_64-linux
@@ -431,10 +437,7 @@ auto:
         --set rust.jemalloc
         --set rust.lto=thin
         --set rust.codegen-units=1
-      # Ensure that host tooling is built to support our minimum support macOS version.
-      MACOSX_DEPLOYMENT_TARGET: 10.12
-      MACOSX_STD_DEPLOYMENT_TARGET: 10.12
-      <<: *env-macos-xcode
+      <<: [*env-macos-x86_64-target, *env-macos-xcode]
       DIST_REQUIRE_ALL_TOOLS: 1
       CODEGEN_BACKENDS: llvm,cranelift
     <<: *job-macos
@@ -445,11 +448,8 @@ auto:
       # Mac Catalyst cannot currently compile the sanitizer:
       # https://github.com/rust-lang/rust/issues/129069
       RUST_CONFIGURE_ARGS: --enable-sanitizers --enable-profiler --set rust.jemalloc --set target.aarch64-apple-ios-macabi.sanitizers=false --set target.x86_64-apple-ios-macabi.sanitizers=false
-      # Ensure that host tooling is built to support our minimum support macOS version.
-      # FIXME(madsmtm): This might be redundant, as we're not building host tooling here (?)
-      MACOSX_DEPLOYMENT_TARGET: 10.12
-      MACOSX_STD_DEPLOYMENT_TARGET: 10.12
-      <<: *env-macos-xcode
+      # FIXME(madsmtm): Setting the target might be redundant, as we're not building host tooling here (?)
+      <<: [*env-macos-x86_64-target, *env-macos-xcode]
     <<: *job-macos
 
   - name: dist-aarch64-apple