Changes

chore(pingcap/tiflow): update latest Go 1.25 CI images for tiflow jobs (#4578)

### What

Update TiFlow latest CI images to the newer Go 1.25 image tag:

- `ghcr.io/pingcap-qe/ci/jenkins:v2026.4.12-10-gc29110c-go1.25` for
jenkins job
- `ghcr.io/pingcap-qe/ci/base:v2026.4.12-10-gc29110c-go1.25` for the
Prow unit test job

### Why

TiFlow PR pingcap/tiflow#12628 updates `go.mod` to `go 1.25.9`.
Some CI jobs were still running with older Go 1.25 images, causing
errors like:
```text
compile: version "go1.25.9" does not match go tool version "go1.25.8" 
``` 
### Test result
I have run replay tests for all failed tasks. The Go version mismatch
issue is now fully resolved. The remaining failures are either
integration test failures inherent to the TiFlow PR itself, or runtime
issues on individual Jenkins/K8s agents. These are not directly related
to the current upgrade of the Go image.

---------

Signed-off-by: lyb <yebin.li@pingcap.com>
 (commit: ae17de4)