Update actions/stale action to v8

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
actions/stale	action	major	v7 -> v8

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Release Notes

actions/stale

v8

Compare Source

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Configuration

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[codecov]

Codecov Report

Merging #414 (9701995) into main (617ad55) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #414   +/-   ##
=======================================
  Coverage   47.69%   47.69%           
=======================================
  Files           4        4           
  Lines         478      478           
=======================================
  Hits          228      228           
  Misses        250      250           

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