Merge remote-tracking branch 'upstream/master' into airbrake-initial

# Conflicts:
#	packages/app/package.json

.changeset/quiet-carpets-shake.md

@@ -0,0 +1,7 @@
+---
+'@backstage/plugin-kubernetes': patch
+'@backstage/plugin-pagerduty': patch
+'@backstage/plugin-splunk-on-call': patch
+---
+
+Clean up emptystate.svg image, removing wrong white artifact from the background

.changeset/tender-cars-look.md

@@ -0,0 +1,5 @@
+---
+'@backstage/backend-test-utils': patch
+---
+
+Bump `testcontainers` dependency to version `8.1.2`