dockerfile: update go version

The go version embedded in the dockerfile has fallen out of date,
bump it up.

Signed-off-by: John Mulligan <jmulligan@redhat.com>

Author: phlogistonjohn

Dockerfile

@@ -1,5 +1,5 @@
 # Build the manager binary
-FROM docker.io/golang:1.24 as builder
+FROM docker.io/golang:1.25 as builder
 ARG GIT_VERSION="(unset)"
 ARG COMMIT_ID="(unset)"
 ARG ARCH=""