not allow use swc target and env configuration toghether

[hardfist]

we should not allow use jsc.target and env toghether, since they are incompatible and may cause unexpected behavior

[hardfist]

guidance

you can use emit_diagnostic generate warnings for conflict options for rspack_loader_swc https://github.com/web-infra-dev/rspack/blob/main/crates/rspack_loader_swc/src/lib.rs#L80

[Hamzakh777]

assign it to me @hardfist

[hardfist]

thanks