4.5.1

Special thanks to the contributors that made this release happen: @cjp256, @kenvandine, @nessita, @philroche and @sergiusens

Full list of changes

• More improvements for using python3.8 from within a snap @kenvandine (#3430)
• Allow revoking validation assertions (LP: #1912332) @nessita (#3433)
• spread tests: remove legacy plugin tests @cjp256 (#3432)
• godeps spread test: use latest/stable go snap @cjp256 (#3431)
• plugins v1: Pin pip to supported versions @philroche (#3428)
• cli: remove experimental notice for compression @cjp256 (#3421)
• Ensure PYTHONPATH is appropriate for building packages with gnome-3-38 @kenvandine (#3424)
• Ensure PYTHONPATH is properly set for gnome-3-34 builds @kenvandine (#3426)
• Revert "cli: allow validation assertions to be revoked (#3417)" @sergiusens (#3422)
• Include SDK snap paths in ACLOCAL_PATH @kenvandine (#3419)
• plainbox spread tests: set tasks to manual @cjp256 (#3420)