Bump kindest/node from v1.27.3 to v1.28.0 in /conformance/tests (#982)

Bumps kindest/node from v1.27.3 to v1.28.0.

---
updated-dependencies:
- dependency-name: kindest/node
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

conformance/tests/Dockerfile

@@ -1,6 +1,6 @@
 # syntax=docker/dockerfile:1.5
 # this is here so we can grab the latest version of kind and have dependabot keep it up to date
-FROM kindest/node:v1.27.3
+FROM kindest/node:v1.28.0
 
 FROM golang:1.21