ci: drop unnecessary go get command

Not sure why that was added at some point, but it doesn't seem
necessary, and even if it was `go install` should be used.

Signed-off-by: Jakub Sokołowski <jakub@status.im>

_assets/ci/Jenkinsfile.ios

@@ -54,7 +54,6 @@ pipeline {
 
     stage('Compile') { steps { dir(env.REPO) {
       sh 'make statusgo-ios'
-      sh 'go get golang.org/x/tools/go/packages'
       dir('build/bin') {
         sh 'zip -r status-go-ios.zip Statusgo.framework'
         sh "cp status-go-ios.zip ${env.ARTIFACT}"