Add 1.24.0 release

• Edit release notes here: https://notes.gstreamer.org/cZk8VFTeT2e4GE04m5eBHQ# (GStreamer developers can login in with gitlab) (locked now, no longer editable, thanks everyone!)

Release notes todo

• clean up / re-organise Rust plugins section
• add stats / contributors (@tpm)
• complete gstvideo section (@tpm)
• complete RTP section (@tpm)
• D3D11 section (@seungha.yang)
• D3D12 section (@seungha.yang)
• va section
• cerbero section (@nirbheek or @tpm)
• adaptivedemux section review by @bilboed
• complete Matrix section (@tpm)
• analytics section (@ocrete)
• gst-editing-services (@thiblahute ?)
• gst-validate (@thiblahute ?)
• video4linux / allocators / wayland (@ndufresne ?)
• MSDK section? (@tpm)
• NVIDIA / CUDA (@seungha.yang)
• remove any remaining 'This section will be completed in due course' and FIXME (@tpm)
• highlights section, do at very end (@tpm)
• update release date at top (@tpm)