Change builder image

Stream 8 seems to be offline and we fail to pull RPMs from the
repositories.

Using dedicated Go base image instead.

Signed-off-by: Petr Horacek <[email protected]>

Author: phoracek

cmd/Dockerfile

@@ -1,11 +1,8 @@
-FROM quay.io/centos/centos:stream8 as builder
+FROM quay.io/projectquay/golang:1.18 as builder
 
 RUN mkdir /workdir
 WORKDIR /workdir
 
-COPY go.mod .
-RUN dnf install -y golang-$(sed -En 's/^go +(.*+)$/\1/p' go.mod).*
-
 COPY . .
 
 ENV GOOS linux