meson: orc-test is not required

This is especially never available on iOS.
8 jobs for <span class="ref-name">fix-orc-test-ios</span> in 16 minutes and 50 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Preparation
passed #95115
gst indent

00:00:15

passed #95114
manifest

00:00:18

 
  Build
passed #95116
build fedora x86_64

00:01:58

 
  Test
passed #95117
check fedora

00:04:06

 
  Full Builds
passed #95118
build android arm64 api28

00:03:41

passed #95120
build cerbero cross win32

00:06:16

passed #95121
build cerbero cross win64

00:06:45

passed #95119
build cerbero fedora x86_64

00:08:08