Add logging checkstye rule

Add checkstyle rule to ensure SLF4J is not used.

Closes gh-14911

src/checkstyle/checkstyle-suppressions.xml

@@ -24,9 +24,13 @@
 	<suppress files="Ansi.*\.java" checks="JavadocStyle" />
 	<suppress files="LogLevel\.java" checks="JavadocVariable" />
 	<suppress files="HelpMojo\.java" checks=".*"/>
-	<suppress files="[\\/]org.springframework.boot.configurationprocessor.json[\\/].*\.java$" checks=".*"/>
+	<suppress files="[\\/]org.springframework.boot.configurationprocessor.json[\\/].*\.java$" checks=".*" />
 	<suppress files="TripType\.java" checks="JavadocVariable" />
 	<suppress files="Rating\.java" checks="JavadocVariable" />
 	<suppress files="Direction\.java" checks="JavadocVariable" />
-	<suppress files="JooqExamples\.java" checks="AvoidStaticImport"/>
+	<suppress files="JooqExamples\.java" checks="AvoidStaticImport" />
+	<suppress files="LoggingApplicationListenerIntegrationTests\.java" checks="IllegalImport" />
+	<suppress files="SpringBootJoranConfiguratorTests\.java" checks="IllegalImport" />
+	<suppress files="EmbeddedMongoAutoConfiguration\.java" checks="IllegalImport" />
+	<suppress files="LogbackMetricsAutoConfiguration\.java" checks="IllegalImport" />
 </suppressions>

src/checkstyle/checkstyle.xml

@@ -9,7 +9,7 @@
 			<property name="illegalPkgs"
 				value="^sun.*, ^org\.apache\.commons\.(?!compress|dbcp2|lang|lang3|logging|pool2).*, ^com\.google\.common.*, ^org\.flywaydb\.core\.internal.*" />
 			<property name="illegalClasses"
-				value="^reactor\.core\.support\.Assert, ^org\.junit\.rules\.ExpectedException" />
+				value="^reactor\.core\.support\.Assert, ^org\.junit\.rules\.ExpectedException, ^org\.slf4j\.LoggerFactory" />
 		</module>
 		<module
 			name="com.puppycrawl.tools.checkstyle.checks.imports.ImportControlCheck">