Remove defunct in.place argument to droplevels() method

[MichaelChirico]

Finishing the deprecation cycle: #6316 -> #6652

[MichaelChirico]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• Simplify error for := under with=FALSE #6834
• Remove defunct in.place argument to droplevels() method #6833 👈 (View in Graphite)
• Remove defunct autostart from fread() #6832
• Remove defunct 'logicalAsInt` from fwrite #6831
• master

This stack of pull requests is managed by Graphite. Learn more about stacking.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Please upload report for BASE (depr-autostart@88edda8). Learn more about missing BASE report.

Additional details and impacted files

@@                Coverage Diff                @@
##             depr-autostart    #6833   +/-   ##
=================================================
  Coverage                  ?   98.64%           
=================================================
  Files                     ?       79           
  Lines                     ?    14638           
  Branches                  ?        0           
=================================================
  Hits                      ?    14440           
  Misses                    ?      198           
  Partials                  ?        0           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[github-actions]

Generated via commit d35148a

Download link for the artifact containing the test results: ↓ atime-results.zip

Task	Duration
R setup and installing dependencies	4 minutes and 35 seconds
Installing different package versions	8 minutes and 8 seconds
Running and plotting the test cases	2 minutes and 19 seconds