fix: invalid multiline_func_header value

[gtg7784]

This PR fixes invalid multiline_func_header value in the foundry.toml file.

When I try to build the project using yarn build, it shows error log like this.

failed to extract foundry config:
foundry config error: unknown variant: found `params_first_multi`, expected `one of `params_first`, `attributes_first`, `all`` for setting `fmt.multiline_func_header`
Because of using deprecated value for the multiline_func_header.

Fixing issue with changing multiline_func_header to params_first