Clean up native-image.properties by removing JUnit entries

Author: diegomarquezp

src/main/resources/META-INF/native-image/com.google.cloud/google-cloud-spanner-jdbc/native-image.properties

@@ -7,10 +7,3 @@ Args = --initialize-at-build-time==com.google.cloud.spanner.IntegrationTestEnv,\
   com.google.cloud.spanner.Dialect$1,\
   com.google.spanner.admin.database.v1.DatabaseDialect,\
   com.google.spanner.admin.database.v1.DatabaseDialect$1,\
-  org.junit.runners.MethodSorters,\
-  org.junit.runners.Parameterized,\
-  org.junit.runner.RunWith,\
-  org.junit.FixMethodOrder,\
-  org.junit.experimental.categories.Category,\
-  org.junit.runners.parameterized.BlockJUnit4ClassRunnerWithParameters,\
-  org.junit.runners.model.FrameworkField,\