ci: use Ninja on macOS

.github/workflows/main.yml

@@ -67,6 +67,7 @@ jobs:
           env:
             CC: clang
             CMAKE_OPTIONS: -DREGEX_BACKEND=regcomp_l -DDEPRECATE_HARD=ON -DUSE_LEAK_CHECKER=leaks -DUSE_GSSAPI=ON
+            CMAKE_GENERATOR: Ninja
             PKG_CONFIG_PATH: /usr/local/opt/openssl/lib/pkgconfig
             SKIP_SSH_TESTS: true
             SKIP_NEGOTIATE_TESTS: true
@@ -181,6 +182,7 @@ jobs:
           env:
             CC: clang
             CMAKE_OPTIONS: -DREGEX_BACKEND=regcomp_l -DDEPRECATE_HARD=ON -DUSE_LEAK_CHECKER=leaks -DUSE_GSSAPI=ON -DEXPERIMENTAL_SHA256=ON
+            CMAKE_GENERATOR: Ninja
             PKG_CONFIG_PATH: /usr/local/opt/openssl/lib/pkgconfig
             SKIP_SSH_TESTS: true
             SKIP_NEGOTIATE_TESTS: true

ci/setup-osx-build.sh

@@ -3,6 +3,6 @@
 set -ex
 
 brew update
-brew install pkgconfig libssh2
+brew install pkgconfig libssh2 ninja
 
 ln -s /Applications/Xcode.app/Contents/Developer/usr/lib/libLeaksAtExit.dylib /usr/local/lib