Bump golang from 1.25.5 to 1.26rc2 in the docker-dependencies group

Bumps the docker-dependencies group with 1 update: golang.


Updates `golang` from 1.25.5 to 1.26rc2

---
updated-dependencies:
- dependency-name: golang
  dependency-version: 1.26rc2
  dependency-type: direct:production
  dependency-group: docker-dependencies
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Dockerfile

@@ -1,5 +1,5 @@
 # Build the manager binary
-FROM --platform=$BUILDPLATFORM golang:1.25.5 AS builder
+FROM --platform=$BUILDPLATFORM golang:1.26rc2 AS builder
 
 ARG GOARCH=''