chore: Update ghcr.io/grafana/grafana-build-tools Docker tag to v1.21.3

grafanarenovatebot[bot] · mem · commit 07539f9e769b · 2025-10-15T08:45:55.000-06:00
diff --git a/.gbt.mk b/.gbt.mk
@@ -1 +1 @@
-GBT_IMAGE=ghcr.io/grafana/grafana-build-tools:v1.21.2
+GBT_IMAGE=ghcr.io/grafana/grafana-build-tools:1.21.3

Original file line number	Diff line number	Diff line change
`@@ -1 +1 @@`
`1`		`-GBT_IMAGE=ghcr.io/grafana/grafana-build-tools:v1.21.2`
	`1`	`+GBT_IMAGE=ghcr.io/grafana/grafana-build-tools:1.21.3`