ci: use not deprecated macOS (#1235)

.github/workflows/insider-macos.yml

@@ -28,7 +28,7 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - runner: macOS-10.15
+          - runner: macos-12
             vscode_arch: x64
           - runner: [self-hosted, macOS, ARM64]
             vscode_arch: arm64