glib: update to 2.74

• Need to keep macOS/iOS on the older version until we can drop the Cocoa mainloop patches, see #323 (closed). (not any more, dropped those in !1023 (merged))

ToDo

• gst-plugins-base/-bad: Fix or work around g_socket_client_set_tls_validation_flags() / g_socket_client_get_tls_validation_flags() deprecation in GLib 2.72: gstreamer!2494 (merged)
• glib: Get rid of Cocoa main loop patch (#323 (closed))
• glib @ msvc: fix libintl lookup (or proxy-intl subproject), unclear why it happens we have proxy-libintl in deps (WIP patch, needs upstreaming)
• glib @ cross-android, cross-windows: fix pcre subprojects build: ERROR: Tried to access compiler for language "c", not specified for build machine. (patch, android later fails in some locale thing)
• glib @ uwp: fix up patch list or keep at 2.62 as well
• Bump glib-networking (patch) (included in commit list now)
• Bump gobject-introspection