Update golang:1.23.4-alpine Docker digest to 9a31ef0 (#397)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Dockerfile

@@ -1,5 +1,5 @@
 # compile
-FROM golang:1.23.4-alpine@sha256:9bfa54e3a85920df66ecf1c4979dfdf88baa80ca9752adda442713863087ef18 AS compile
+FROM golang:1.23.4-alpine@sha256:9a31ef0803e6afdf564edc8ba4b4e17caed22a0b1ecd2c55e3c8fdd8d8f68f98 AS compile
 WORKDIR /go/src/github.com/utopia-planitia/k8s-gitlab-gc/
 
 COPY go.mod .