fix(deps): upgrade wasmtime to 42.0.2 to resolve security advisories

Upgrade wasmtime and wasmtime-wasi from 41.0.1 to 42.0.2 to fix 7
security vulnerabilities flagged by cargo-deny:

- RUSTSEC-2026-0089: sandbox escape via Cranelift aarch64
- RUSTSEC-2026-0091: OOB write in component model string transcoding
- RUSTSEC-2026-0092: panic on misaligned UTF-16 strings
- RUSTSEC-2026-0093: heap OOB read in UTF-16 to latin1+utf16 transcoding
- RUSTSEC-2026-0094: improperly masked table.grow return value (Winch)
- RUSTSEC-2026-0095: sandbox-escaping memory access (Winch)
- RUSTSEC-2026-0096: miscompiled guest heap access on aarch64

Also removes the deprecated Config::async_support() call which no
longer has any effect in wasmtime 42.

Signed-off-by: StreamKit Devin <devin@streamkit.dev>
Co-Authored-By: Claudio Costa <cstcld91@gmail.com>

Author: streamkit-devin