Only enable minimum set of wasmtime features

[alexsnaps]

Updated wasmtime to the latest release and removed some of the otherwise default features that are actually not needed afaict

Some introduce the need for "newer" toolchains (e.g. wat) that might be an issue for some test environments out there, despite the dependency actually not being required.

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[alexsnaps]

(Crap, I'll redo this PR with my RH, Google CLA approved email), will also update the other deps)

[alexsnaps]

Actually don't think that outdated dep is "fixable":

postcard->embedded-io  0.6.1    0.4.0   0.4.0   Normal  ---

given:

name = "postcard"
version = "1.0.10"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "5f7f0a8d620d71c457dd1d47df76bb18960378da56af4527aaa10f515eee732e"
dependencies = [
 "cobs",
 "embedded-io 0.4.0",
 "embedded-io 0.6.1",
 "serde",
]

Where

└── wasmtime v24.0.0
    […]
     ├── postcard v1.0.10

And I'm not even sure it actually gets pulled in, according to cargo --tree and the features of the crate not being in use afaict