Fixes an error from Meson: ../subprojects/gst-plugins-bad/tests/validate/meson.build:16:93: ERROR: Unknown variable "soundtouch_dep" Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/9190>
Fixes an error from Meson: ../subprojects/gst-plugins-bad/tests/validate/meson.build:16:93: ERROR: Unknown variable "soundtouch_dep" Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/9190>