* ci: add Jenkins user to dockerfile
Otherwise the `$HOME` variable is not set which results in:
```
+ make test
go test -v ./...
failed to initialize build cache at /.cache/go-build: mkdir /.cache: permission denied
Makefile:31: recipe for target 'test' failed
```
Signed-off-by: Jakub Sokołowski <jakub@status.im>
* ci: use crazymax/xgo:1.18.1 docker image as base
The old `xgo` image does not work:
```
../../../../pkg/mod/github.com/ethereum/go-ethereum@v1.10.26/common/test_utils.go:27:18: undefined: os.ReadFile
note: module requires Go 1.17
Makefile:31: recipe for target 'test' failed
```
Signed-off-by: Jakub Sokołowski <jakub@status.im>
Signed-off-by: Jakub Sokołowski <jakub@status.im>
