rarfile v4.2

Features:

• Support unrar-free >= 0.2.0. [#103]
• Add RarFile.is_solid to check if archive uses solid compression. [#101]

Fixes:

• Support old multi-volume archives better where ENDARC does not contain NEXTVOL. [#97]

Cleanups:

• ci: Drop Python 3.7, add 3.12
• ci: upgrade actions