ci/local.sh broken

Running `ci/local.sh` does not work.

```sh
$ ./ci/local.sh ../wasmtime
cp: ../wasmtime/crates/c-api/wasm-c-api/include/*.h: No such file or directory
```

After a run of `cargo build` and `cargo build -p wasmtime-c-api` in wasmtime, `crates/c-api/wasm-c-api` does not exist.

Removing the last line, `cp "$wasmtime"/crates/c-api/wasm-c-api/include/*.h build/include` of `local.sh` makes the script succeed.

However, then `go test` (like suggested in the instructions) fails:

```sh
$ go test
# github.com/bytecodealliance/wasmtime-go/v22
# [github.com/bytecodealliance/wasmtime-go/v22]
In file included from ./config.go:4:
In file included from ./build/include/wasmtime.h:182:
./build/include/wasi.h:12:10: fatal error: 'wasmtime/conf.h' file not found
#include
^~~~~~~~~~~~~~~~~
1 error generated.
FAIL github.com/bytecodealliance/wasmtime-go/v22 [build failed]
```

`build/include/wasmtime/conf.h` does indeed not exist, though `build/include/wasmtime/conf.h.in` does