Fix PHPUnit 11 compatibility

[rgson]

Fixes the errors in PHPUnit 11:

There were 4 PHPUnit errors:                                                                                                                                                        
                                                                                                                                                                                    
1) Giggsey\Locale\Tests\DisplayRegionTest::testGetDisplayRegion                                                                                                                     
The data provider specified for Giggsey\Locale\Tests\DisplayRegionTest::testGetDisplayRegion is invalid                                                                             
Data Provider method Giggsey\Locale\Tests\DisplayRegionTest::dataDisplayRegions() is not static                                                                                     
                                                                                                                                                                                    
giggsey/Locale/tests/DisplayRegionTest.php:16                                                                                                                
                                                                                                                                                                                    
2) Giggsey\Locale\Tests\PrimaryLanguageTest::testGetPrimaryLanguage                                                                                                                 
The data provider specified for Giggsey\Locale\Tests\PrimaryLanguageTest::testGetPrimaryLanguage is invalid                                                                         
Data Provider method Giggsey\Locale\Tests\PrimaryLanguageTest::dataListOfPrimaryLanguages() is not static                                                                           
                                                                                                                                                                                    
giggsey/Locale/tests/PrimaryLanguageTest.php:15                                                                                                              
                                                                                                                                                                                    
3) Giggsey\Locale\Tests\PrimaryLanguageTest::testUnderscoreOrDash                                                                                                                   
The data provider specified for Giggsey\Locale\Tests\PrimaryLanguageTest::testUnderscoreOrDash is invalid                                                                           
Data Provider method Giggsey\Locale\Tests\PrimaryLanguageTest::dataUnderscoreOrDash() is not static                                                                                 
                                                                                                                                                                                    
giggsey/Locale/tests/PrimaryLanguageTest.php:250                                                                                                             
                                                                                                                                                                                    
4) Giggsey\Locale\Tests\RegionTest::testGetRegion                                                                                                                                   
The data provider specified for Giggsey\Locale\Tests\RegionTest::testGetRegion is invalid                                                                                           
Data Provider method Giggsey\Locale\Tests\RegionTest::dataListOfRegions() is not static                                                                                             
                                                                                                                                                                                    
giggsey/Locale/tests/RegionTest.php:15