grilo{,-plugins}: update to 0.3.16

[chrysos349]

split into a separate pr, according to @oreo639's recommendation (#48752 (comment)).

Testing the changes

• I tested the changes in this PR: YES

Local build testing

• I built this PR locally for my native architecture, (x86_64)
• I built this PR locally for these architectures (if supported. mark crossbuilds):
  • aarch64-musl x
  • armv7l x
  • armv6l-musl x

[oreo639]

grilo-plugins should probably also be updated

[chrysos349]

done

[oreo639]

Replace the patch and just add .strip('//') to the end of gobject_introspection.get_variable(pkgconfig: 'girdir', pkgconfig_define: ['datadir', '${datadir}']). (it gets messed up because we add pc_sysrootdir)