Exporting symbols seems to embed them in the WASM exports section which
causes wasmtime to fail: https://github.com/bytecodealliance/wasmtime/issues/2587
As a workaround, it is possible to specify the `--allow-unknown-exports`
flag on wasmtime.
But as discussed in the above linked issue, this seems to only be a
workaround. For the Rust compiler the fix was to remove the
`--export-dynamic` linker flag when targeting `wasm32-wasi`:
https://github.com/rust-lang/rust/pull/81255
Which is waht this commit does for Tinygo too.