update to Nextcloud 29

[szaimen]

Tasks

TODO:

• Wait for at least 29.0.1
• Wait for publish new images after recent PRs are merged and tested #4653 to become stable

Issues:

• https://github.com/nextcloud/server/issues?q=is%3Aopen+is%3Aissue++label%3A29-feedback+
• Revert: "Check datadirectory owner, not config owner." server#45302
• change the rewrite for remote.php #4651
• [Bug]: occ db:convert-type broken since PrimaryReadReplicaConnection support added server#45257

Apps not compatible:

• increase aio version to 29 aio-app: increase version #4770
• other bundled apps
• further apps

Test:

• test new instance?
• check if all included features work
  • ClamAV
  • Collabora
  • Fulltextsearch
  • Imaginary (for previews of heic, heif, illustrator, pdf, svg, tiff and webp. Imaginary is currently incompatible with server-side-encryption)
  • Talk
  • talk recording
  • docker-socket-proxy
• check admin overview
• check each other overview
• check if nextcloud-aio app works
• remove potentially added note in the aio interface about nextcloud 28 by changing newMajorVersion to '' https://github.com/nextcloud/all-in-one/compare/enh/4564/hide-update-notice?expand=1
• postgres: update to 16 #4772
• revert "set NEXTCLOUD_MOUNT to rshared #2601" #4755
• ...