Merge branch 'stable-3.6' into stable-3.7

* stable-3.6:
  Use orNull instead of explicit null default
  Fix IterableOnce foreach deprecation warning
  Fix array splat deprecation warning
  Fix .toStream deprecation warning
  Fix deprecated `l` for Longs
  Remove use of deprecated JavaConverters class
  Fix TraversableOnce deprecation warnings
  Fix procedure syntax deprecation warnings
  Fix reflective structural type access warning
  Fix unable to check type warnings
  Fix override without parameter list warning
  Update Scala to 2.13.10
  Bump scalatest to 3.2.16
  Fix feature warnings
  Bump sbt to 1.8.3
  Add gitignore entries
  Set Gerrit to v3.6.0-rc0

Change-Id: Ic4b86f5ad214c1cd53bd3bacc949173a769abe3e
diff --git a/build.sbt b/build.sbt
index 144f784..6f5750d 100644
--- a/build.sbt
+++ b/build.sbt
@@ -1,6 +1,6 @@
 enablePlugins(GitVersioning)
 
-val gerritApiVersion = "3.6.0-rc0"
+val gerritApiVersion = "3.7.0-rc3"
 
 val pluginName = "analytics"