Upgrade instructions to 3.5.0rc1 (from 3.4.6) seem incorrect - no git pull/fetch step

[DalekDave]

Steps to reproduce the problem

1. Follow upgrade instructions at https://github.com/mastodon/mastodon/releases/tag/v3.5.0rc1

2. There is no git pull/fetch step for the new source code

3. Follow all instructions for non-Docker scenario

4. All steps conclude successfully, including restart, and but Mastodon version number remains at 3.4.6 on the Mastodon instance's About page

5. Start upgrade process again, commencing with git fetch && git checkout -f v3.5.0rc1

   Seems to complete OK, with following message:

   Previous HEAD position was 93a6c14 Fix insufficient sanitization of report comments (Fix insufficient sanitization of report comments #17430)
   HEAD is now at 4bdce2c Bump version to 3.5.0rc1 (Bump version to 3.5.0rc1 #17618)

6. Execute bundle install

   I get the error message : rbenv: version `3.0.3' is not installed (set by /home/mastodon/live/.ruby-version)

7. Bite fingers nervously and carefully do not restart Mastodon instance again before getting adivice/solution from developers

...

Expected behaviour

Version on instance About page should incerment to 3.5.0rc1

Actual behaviour

Version on instance's About page remains at 3.4.6

Specifications

Previous HEAD position was 93a6c14 Fix insufficient sanitization of report comments (#17430)
HEAD is now at 4bdce2c Bump version to 3.5.0rc1 (#17618)

[benharri]

Might want to add a note in the changelog for updating ruby with rbenv

[shleeable]

It is true.. the git fetch && git checkout v3.5.0rc1 is missing from the notes.

Hopefully you've got the problem sorted tho

[ClearlyClaire]

Yeah, as @benharri pointed out, the release notes are lacking instructions regarding updating Ruby with rbenv.

Update the list of ruby versions available to rbenv if needed, then build Ruby 3.0.3 with RUBY_CONFIGURE_OPTS=--with-jemalloc rbenv install 3.0.3.

I edited the release notes to add some more information about this as well as summarize dependencies.