devel/libwasmtime: Update 49.0.2 => 50.0.1

This update fixes twenty-five security advisories: twenty fixed upstream
in 49.0.3 and 49.0.4, and five fixed in 50.0.1.

Changelogs:
https://github.com/bytecodealliance/wasmtime/releases/tag/v49.0.3
https://github.com/bytecodealliance/wasmtime/releases/tag/v49.0.4
https://github.com/bytecodealliance/wasmtime/releases/tag/v50.0.0
https://github.com/bytecodealliance/wasmtime/releases/tag/v50.0.1

Security: 57e6e702-cd69-11f1-b0e3-74563cf85f9d
Security: c0892724-d4a0-11f1-8df4-74563cf85f9d
Approved by: jrm (mentor)
Differential Revision: https://reviews.freebsd.org/D60940