Creder/allowing for multibranch custom workspaces (#62)

* Updates to build with java21

* CI updates for Java 21

* Additional CI updates

* Additional CI fixes

* Additional CI fixes

* Extra fixes

* Extra fixes

* Additional testing changes

* Adding updates to allow us to set custom workspaces

* Additional updates

* Additional updates

* Git cruft fix

* Custom workspace improvements

* Fix: Remove remaining merge conflict markers

- Removed conflict markers from Pipeline.kt
- Removed conflict markers from DockerAgent.kt
- Build verified successful
- All tests passing

* Version increment

* Fixing workspace path

---------

Co-authored-by: Caleb Reder <[email protected]>

Author: reder9

core/src/main/kotlin/com/code42/jenkins/pipelinekt/core/Pipeline.kt

@@ -82,7 +82,7 @@ data class Pipeline(
             writer.writeln("if (env.BRANCH_NAME) {")
             val innerWriter = writer.inner()
             innerWriter.writeln("def safeBranch = env.BRANCH_NAME.replaceAll(/[^A-Za-z0-9._-]/, '_')")
-            innerWriter.writeln("customWorkspacePath = \"../\${env.JOB_NAME}-\${safeBranch}\"")
+            innerWriter.writeln("customWorkspacePath = \"./workspace//\${env.JOB_NAME}-\${safeBranch}\"")
             writer.writeln("}")
             writer.writeln("")
         }