POM: remove scijava-optional dependency

As indicated by mvn dependency:analyze, we don't directly depend on scijava-optional, only transiently through scijava-table.

Author: imagejan

pom.xml

@@ -113,10 +113,6 @@ Wisconsin-Madison and University of Konstanz.</license.copyrightOwners>
 			<groupId>org.scijava</groupId>
 			<artifactId>scijava-table</artifactId>
 		</dependency>
-		<dependency>
-			<groupId>org.scijava</groupId>
-			<artifactId>scijava-optional</artifactId>
-		</dependency>
 
 		<!-- Test scope dependencies -->
 		<dependency>