Remove unused imports (#13002)

These imports have been copied by accident from another test in this class.

Author: darxriggs

grails-test-suite-uber/src/test/groovy/grails/compiler/GrailsCompileStaticCompilationErrorsSpec.groovy

@@ -174,8 +174,6 @@ class SomeClass {
         def c = gcl.parseClass('''
 package grails.compiler
 
-import groovy.transform.TypeCheckingMode
-
 @GrailsCompileStatic
 class SomeClass implements grails.validation.Validateable {
     String name
@@ -197,8 +195,6 @@ class SomeClass implements grails.validation.Validateable {
         def c = gcl.parseClass('''
 package grails.compiler
 
-import groovy.transform.TypeCheckingMode
-
 @GrailsCompileStatic
 @grails.persistence.Entity
 class SomeClass implements grails.validation.Validateable {
@@ -233,8 +229,6 @@ class SomeClass implements grails.validation.Validateable {
         def c = gcl.parseClass('''
 package grails.compiler
 
-import groovy.transform.TypeCheckingMode
-
 @GrailsCompileStatic
 class SomeClass implements grails.validation.Validateable {
 
@@ -341,8 +335,6 @@ class SomeSubClass extends SomeClass implements grails.validation.Validateable {
         def c = gcl.parseClass('''
 package grails.compiler
 
-import groovy.transform.TypeCheckingMode
-
 @GrailsCompileStatic
 class SomeClass {