ci: pin heavy macOS jobs to studio runner

rust-tests, macOS build matrix, and macOS release build use
[macOS, ARM64, studio] label for cache affinity and faster builds.
Lighter jobs (lint, playwright) remain on either runner.

Author: pythoninthegrass

.github/workflows/release.yml

@@ -32,7 +32,7 @@ jobs:
     if: >
       github.event_name == 'release' ||
       inputs.platform == 'all' || inputs.platform == 'macos' || inputs.platform == ''
-    runs-on: [macOS, ARM64]
+    runs-on: [macOS, ARM64, studio]
     timeout-minutes: 30
 
     steps:

.github/workflows/test.yml

@@ -80,7 +80,7 @@ jobs:
       matrix:
         include:
           - platform: macos
-            os: [macOS, ARM64]
+            os: [macOS, ARM64, studio]
             target: aarch64-apple-darwin
           - platform: linux
             os: blacksmith-4vcpu-ubuntu-2404
@@ -218,7 +218,7 @@ jobs:
   rust-tests:
     name: Rust Tests with Coverage
     needs: rust-lint
-    runs-on: [macOS, ARM64]
+    runs-on: [macOS, ARM64, studio]
     timeout-minutes: 10
     env:
       CARGO_INCREMENTAL: 1