use common beam version in gradle plugin

theodolite-benchmarks/buildSrc/src/main/groovy/theodolite.beam.gradle

@@ -18,6 +18,8 @@ repositories {
     }
 }
 
+def apacheBeamVersion =  '2.22.0' //'2.27.0' // '2.34.0'
+
 dependencies {
     // These dependencies are used internally, and not exposed to consumers on their own compile classpath.
     implementation('org.industrial-devops:titan-ccp-common:0.1.0-SNAPSHOT') { changing = true }
@@ -27,14 +29,14 @@ dependencies {
     implementation 'org.slf4j:slf4j-simple:1.7.25'
     implementation project(':beam-commons')
 
-    implementation group: 'org.apache.beam', name: 'beam-sdks-java-core', version: '2.22.0'
+    implementation group: 'org.apache.beam', name: 'beam-sdks-java-core', version: "${apacheBeamVersion}"
 
-    implementation('org.apache.beam:beam-sdks-java-io-kafka:2.22.0'){
+    implementation("org.apache.beam:beam-sdks-java-io-kafka:${apacheBeamVersion}"){
         exclude group: 'org.apache.kafka', module: 'kafka-clients'
     }
     implementation group: 'org.slf4j', name: 'slf4j-simple', version: '1.7.30'
 
-    runtime 'org.apache.beam:beam-runners-direct-java:2.22.0'
+    runtime "org.apache.beam:beam-runners-direct-java:${apacheBeamVersion}"
     runtime 'org.slf4j:slf4j-api:1.7.32'
     runtime 'org.slf4j:slf4j-jdk14:1.7.32'