v0.12.4

TensorKit v0.12.4

Diff since v0.12.3

Merged pull requests:

• Utility and Quality of life for VectorSpaces (#120) (@lkdvos)
• Bump julia-actions/cache from 1 to 2 (#121) (@dependabot[bot])
• Improve warnings in AD rules (#122) (@lkdvos)
• small fix in backward rule for leftorth, rightorth (#123) (@tangwei94)
• Fix rrules for Fermionic symmetries (#126) (@qmortier)
• Fix undefined tol and remove unused variable in QR and LQ pullback (#127) (@leburgel)

Closed issues:

• ComplexSpace constructor from sector-degeneracy pairs similar to that of GradedSpace? (#119)