[deps]: Update actions/checkout action to v6

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
actions/checkout	action	major	v5.0.0 -> v6.0.1

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Release Notes

actions/checkout (actions/checkout)

v6.0.1

Compare Source

v6.0.0

Compare Source

v5.0.1

Compare Source

What's Changed

• Port v6 cleanup to v5 by @​ericsciple in #​2301

Full Changelog: actions/checkout@v5...v5.0.1

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Configuration

📅 Schedule: Branch creation - "every 2nd week starting on the 2 week of the year before 4am on Monday" (UTC), Automerge - At any time (no schedule defined).

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[bitwarden-bot]

Internal tracking:

• ID: PM-29321
• Link: https://bitwarden.atlassian.net/browse/PM-29321

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.43%. Comparing base (260d81b) to head (a80d90a).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2186   +/-   ##
=======================================
  Coverage   85.43%   85.43%           
=======================================
  Files        1734     1734           
  Lines      146378   146378           
=======================================
  Hits       125058   125058           
  Misses      21320    21320           

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