Update tycho version

to see if it helps w/ JDK 19-EA

Startblock:
   unknown commit is submitted
PiperOrigin-RevId: 448133464

Author: cushon

eclipse_plugin/pom.xml

@@ -32,7 +32,7 @@
 
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-    <tycho-version>2.6.0</tycho-version>
+    <tycho-version>2.7.3</tycho-version>
   </properties>
 
   <dependencies>