chore: Update dependency xk6 to v1.2.3 (#448)

Co-authored-by: grafanarenovatebot[bot] <146220760+grafanarenovatebot[bot]@users.noreply.github.com>

Author: grafanarenovatebot[bot]

versions.yaml

@@ -111,7 +111,7 @@ spectral:
   version: v6.15.0 # renovate: datasource=github-releases depName=spectral packageName=stoplightio/spectral
 
 xk6:
-  version: v1.1.6 # renovate: datasource=github-tags depName=xk6 packageName=grafana/xk6
+  version: v1.2.3 # renovate: datasource=github-tags depName=xk6 packageName=grafana/xk6
 
 yq:
   version: v4.48.1 # renovate: datasource=github-tags depName=yq packageName=mikefarah/yq