Revise v3.8.1

Diff since v3.8.0

Merged pull requests:

• Correctly revise methods defined in external method tables (#904) (@serenity4)
• Path-switching for extensions (#909) (@timholy)
• fixes for Compiler stdlib (#913) (@vtjnash)
• Add PCRE2_jll and Zlib_jll as known stdlibs (#930) (@eschnett)
• Use invokelatest when printing errors after includet (#934) (@Keno)
• Track Core.Compiler under a separate PkgId (#936) (@Keno)
• Remove manifest from docs & bump version (#941) (@serenity4)

Closed issues:

• Revising methods with external method tables fails (#646)
• Revise does not pick up path change for package extensions if I dev a package (#858)
• Revise should replace docstring rather than adding to it (#927)
• Long delay when exiting julia if Revise has been imported (#928)
• CI fails on master (#935)