[macos] add pkg-config to macos-13 image (#7719)

Author: ilia-shipitsin

images/macos/toolsets/toolset-13.json

@@ -75,6 +75,7 @@
             "p7zip",
             "packer",
             "perl",
+            "pkg-config",
             "swiftformat",
             "zstd",
             "gmp",