chore(deps): update golang docker tag to v1.20.9

plural-renovate[bot] · plural-renovate[bot] · commit 1af52585cb6b · 2023-10-06T00:32:10.000Z
diff --git a/Dockerfile b/Dockerfile
@@ -1,5 +1,5 @@
 # Build the manager binary
-FROM golang:1.20.5 as builder
+FROM golang:1.20.9 as builder
 ARG TARGETOS
 ARG TARGETARCH
 
