[Bug]: Build for target iOS fails

## Summary of Bug

Building to `iOS` target fails because of undefined definitions.
## Version

Using v1.2.1

## Steps to Reproduce

* Try to build for iOS target using `gomobile bind -ldflags='-s -w' -target=ios`

Output:
```
/nix/store/gizbq4q5h49ryijyhzx7arlrnkxpf47y-gomobile-unstable-2023-03-01/bin/gomobile: iossimulator/amd64: go build -ldflags -s -w -buildmode=c-archive -o /var/folders/m6/fx641jqn0lq3pzwqkkh60p4c0000gn/T/gomobile-work-3352046974/signing-iossimulator-amd64.a ./gobind failed: exit status 1
# github.com/99designs/keyring
/Users/user/go/pkg/mod/github.com/99designs/keyring@v1.2.1/keychain.go:56:9: query.SetMatchSearchList undefined (type keychain.Item has no field or method SetMatchSearchList)
/Users/user/go/pkg/mod/github.com/99designs/keyring@v1.2.1/keychain.go:56:39: undefined: gokeychain.NewWithPath
/Users/user/go/pkg/mod/github.com/99designs/keyring@v1.2.1/keychain.go:116:45: undefined: gokeychain.Keychain
/Users/user/go/pkg/mod/github.com/99designs/keyring@v1.2.1/keychain.go:125:13: queryItem.SetMatchSearchList undefined (type keychain.Item has no field or method SetMatchSearchList)
/Users/user/go/pkg/mod/github.com/99designs/keyring@v1.2.1/keychain.go:137:9: kcItem.SetAccess undefined (type keychain.Item has no field or method SetAccess)
/Users/user/go/pkg/mod/github.com/99designs/keyring@v1.2.1/keychain.go:147:20: undefined: gokeychain.Keychain
/Users/user/go/pkg/mod/github.com/99designs/keyring@v1.2.1/keychain.go:167:10: kcItem.UseKeychain undefined (type keychain.Item has no field or method UseKeychain)
/Users/user/go/pkg/mod/github.com/99designs/keyring@v1.2.1/keychain.go:182:10: kcItem.SetAccess undefined (type keychain.Item has no field or method SetAccess)
/Users/user/go/pkg/mod/github.com/99designs/keyring@v1.2.1/keychain.go:182:32: undefined: gokeychain.Access
/Users/user/go/pkg/mod/github.com/99designs/keyring@v1.2.1/keychain.go:268:47: undefined: gokeychain.Keychain
/Users/user/go/pkg/mod/github.com/99designs/keyring@v1.2.1/keychain.go:182:32: too many errors
```