Remove older macOS release runner (#25)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

Author: Copilot

.github/workflows/release.yml

@@ -47,10 +47,6 @@ jobs:
             target: aarch64-unknown-linux-gnu
             asset_suffix: linux-arm64
             binary_name: gh-pilot
-          - os: macos-13
-            target: x86_64-apple-darwin
-            asset_suffix: darwin-amd64
-            binary_name: gh-pilot
           - os: macos-14
             target: aarch64-apple-darwin
             asset_suffix: darwin-arm64