build(deps): bump golang from 1.25.6 to 1.26.2

Bumps golang from 1.25.6 to 1.26.2.

---
updated-dependencies:
- dependency-name: golang
  dependency-version: 1.26.2
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

Dockerfile

@@ -1,7 +1,7 @@
 # Update the base image in Makefile when updating golang version. This has to
 # be pre-pulled in order to work on GCB.
 ARG ARCH
-FROM golang:1.25.6 as build
+FROM golang:1.26.2 as build
 
 WORKDIR /go/src/sigs.k8s.io/metrics-server
 COPY go.mod .