Specify Jetty version for jspc plugin.

PiperOrigin-RevId: 800161329
Change-Id: I16a91389a1c3bb3fe929b67879be35e9449bfd27

Author: ludoch

local_runtime_shared_jetty12/pom.xml

@@ -78,6 +78,7 @@
       <plugin>
         <groupId>org.eclipse.jetty.ee8</groupId>
         <artifactId>jetty-ee8-jspc-maven-plugin</artifactId>
+       <version>${jetty12.version}</version>
         <executions>
           <execution>
             <id>jspc</id>