Post 3.8.0 release merge

[westonruter]

Fixes #1796

• Remove no-cache and max-age=0 from bfcache failure conditions
• Simplify logic now that only one directive is checked
• Refactor response mocking
• Bump plugin versions
• Run npm run since
• Remove -beta1 from 1.0.0 since tags
• Generate changelogs
• Use placeholders for CODE in translated string
• Update changelog entry

[github-actions]

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Co-authored-by: westonruter <westonruter@git.wordpress.org>
Co-authored-by: felixarntz <flixos90@git.wordpress.org>

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[codecov]

Codecov Report

Attention: Patch coverage is 57.14286% with 6 lines in your changes missing coverage. Please review.

Project coverage is 65.86%. Comparing base (0615c18) to head (46fc9cb).
Report is 4 commits behind head on trunk.

Files with missing lines	Patch %	Lines
plugins/embed-optimizer/load.php	0.00%	1 Missing ⚠️
plugins/image-prioritizer/load.php	0.00%	1 Missing ⚠️
plugins/optimization-detective/load.php	0.00%	1 Missing ⚠️
plugins/performance-lab/load.php	0.00%	1 Missing ⚠️
plugins/speculation-rules/load.php	0.00%	1 Missing ⚠️
plugins/webp-uploads/load.php	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##            trunk    #1830      +/-   ##
==========================================
- Coverage   65.96%   65.86%   -0.11%     
==========================================
  Files          88       88              
  Lines        6876     6855      -21     
==========================================
- Hits         4536     4515      -21     
  Misses       2340     2340              

Flag	Coverage Δ
multisite	65.86% <57.14%> (-0.11%)	⬇️
single	38.45% <57.14%> (-0.19%)	⬇️

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