Fiat Cryptography v0.0.15

The biggest change of this release is Ltac2 reification and (hopefully) compatibility with Coq 8.15 and 8.16 on Windows. Minimum required versions: Coq 8.15, OCaml 4.08

What's Changed

• Port reification to Ltac2 by @JasonGross in #1361
• Garagedoor opens by @andres-erbsen in #1369
• Zig backend: bump the comptime branch quota up for cast() calls by @jedisct1 in #1360
• Use $$ rather than $ for var so as to not conflict with Ltac2 antiquotations by @JasonGross in #1359
• Makefile fixups by @andres-erbsen in #1393

Full Changelog: v0.0.14...v0.0.15