github: update minimum macOS version to 11.0

10.15 has been EOL for a long time, and the runner that builds a wheel
on macOS automatically updated the version to 11.0 each time with
raising a warning.

This commit doesn't change any behaviour of CI, it silences a warning
and makes 11.0 explicit.

Signed-off-by: Mikhail Koviazin <[email protected]>

Author: mkmkme

.github/workflows/pypi-publish.yaml

@@ -34,7 +34,7 @@ jobs:
         os: [ubuntu-20.04, windows-2019, macos-latest]
     env:
       CIBW_ARCHS_MACOS: "x86_64 universal2 arm64"
-      MACOSX_DEPLOYMENT_TARGET: "10.15"
+      MACOSX_DEPLOYMENT_TARGET: "11.0"
     steps:
       - uses: actions/checkout@v4
         with: