Allow Flyway tests to import internal exception

Closes gh-14989

Author: wilkinsona

src/checkstyle/checkstyle-suppressions.xml

@@ -36,4 +36,5 @@
 	<suppress files="LogbackMetricsAutoConfiguration\.java" checks="IllegalImport" />
 	<suppress files="RemoteUrlPropertyExtractorTests\.java" checks="IllegalImport" />
 	<suppress files="SampleLogbackApplication\.java" checks="IllegalImport" />
+	<suppress files="FlywayAutoConfigurationTests\.java" checks="IllegalImport" />
 </suppressions>