Bump spotbugs-maven-plugin from 3.1.12.2 to 4.0.4 (#48)

Author: dependabot[bot]

pom.xml

@@ -394,7 +394,7 @@
 			<plugin>
 				<groupId>com.github.spotbugs</groupId>
 				<artifactId>spotbugs-maven-plugin</artifactId>
-				<version>3.1.12.2</version>
+				<version>4.0.4</version>
 				<configuration>
 					<effort>Max</effort>
 					<!-- Reports all bugs (other values are medium and max) -->