Update golang Docker tag to v1.21.5

renovate[bot] · web-flow · commit 0720d440a24f · 2023-12-05T23:01:49.000Z
diff --git a/Dockerfile b/Dockerfile
@@ -1,5 +1,5 @@
 # Operator
-FROM golang:1.16.0 AS builder
+FROM golang:1.21.5 AS builder
 RUN mkdir -p /src
 ADD Makefile /
 
