Use GitHub macOS 26 runners (#176)

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ permissions:
 jobs:
   lint:
     name: Lint
-    runs-on: ghcr.io/cirruslabs/macos-runner:tahoe
+    runs-on: macos-26
     timeout-minutes: 30
     steps:
       - uses: actions/checkout@v6
@@ -30,17 +30,9 @@ jobs:
         run: cargo clippy --all-targets --all-features -- -D warnings
 
   test:
-    name: Test on macOS ${{ matrix.macos }}
-    runs-on: ghcr.io/cirruslabs/macos-runner:${{ matrix.runner }}
+    name: Test on macOS 26
+    runs-on: macos-26
     timeout-minutes: 30
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - macos: Sequoia
-            runner: sequoia
-          - macos: Tahoe
-            runner: tahoe
     steps:
       - uses: actions/checkout@v6
       - name: Install Rust

.github/workflows/release.yml

@@ -13,7 +13,7 @@ jobs:
   release:
     name: Release
     if: github.event_name == 'push' && github.ref_type == 'tag'
-    runs-on: ghcr.io/cirruslabs/macos-runner:tahoe
+    runs-on: macos-26
     environment: publish
     timeout-minutes: 60
     steps:
@@ -58,7 +58,7 @@ jobs:
   snapshot:
     name: Release (Dry Run)
     if: github.event_name == 'workflow_dispatch'
-    runs-on: ghcr.io/cirruslabs/macos-runner:tahoe
+    runs-on: macos-26
     timeout-minutes: 60
     steps:
       - uses: actions/checkout@v6