contrib: update libarchive to 3.7.0

It contains all the patches we had.

Changelog: https://github.com/libarchive/libarchive/releases/tag/v3.7.0

New features:

• bsdunzip: new tool ported from FreeBSD)
• drop-in replacement for Info-ZIP unzip, not yet ported for Windows
• 7zip reader: support for Zstandard compression
• 7zip reader: support for ARM64 filter
• zstd filter: support for multi-frame zstd archives

Other notable bugfixes and improvements:

• pax: fix year 2038 problem on platforms with 64-bit time_t
• Windows: Universal Windows Platform (UWP) fixes and improvements
• Windows: bcrypt usage fixes and improvements
• Windows: time function usage fixes and improvements