Fix: Remove use of removed settings dump-default from release workflow

[alexdewar]

Description

I accidentally broke the release workflow in #860 (I noticed because we run it on pushes to main). I'd changed it to generate the bundled settings.toml file using the settings dump-default command and forgot to update it after I changed the command's name.

On reflection, though, I don't think we actually need that file anymore anyway: users can get information about the possible settings by just running muse2 settings edit. So I've just removed it.

Type of change

• Bug fix (non-breaking change to fix an issue)
• New feature (non-breaking change to add functionality)
• Refactoring (non-breaking, non-functional change to improve maintainability)
• Optimization (non-breaking change to speed up the code)
• Breaking change (whatever its nature)
• Documentation (improve or add documentation)

Key checklist

• All tests pass: $ cargo test
• The documentation builds and looks OK: $ cargo doc

Further checks

• Code is commented, particularly in hard-to-understand areas
• Tests added that prove fix is effective or that feature works

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.18%. Comparing base (5c9aba6) to head (93b7f5c).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #873   +/-   ##
=======================================
  Coverage   85.18%   85.18%           
=======================================
  Files          50       50           
  Lines        5300     5300           
  Branches     5300     5300           
=======================================
  Hits         4515     4515           
  Misses        565      565           
  Partials      220      220           

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