meson: Allow usage of externally overridden pkg-config
This MR allows the override from GStreamer's win-pkgconfig subproject to take effect here, letting the cargo-c call work. Otherwise, a pkg-config executable needs to be present in the PATH.
Due to an influx of spam, we have had to impose restrictions on new accounts. Please see this wiki page for instructions on how to get full permissions. Sorry for the inconvenience.
This MR allows the override from GStreamer's win-pkgconfig subproject to take effect here, letting the cargo-c call work. Otherwise, a pkg-config executable needs to be present in the PATH.