chore: update to go v1.25.5

[kalleep]

update to go v1.25.5 and update to new build image created in #5014

[github-actions]

🔍 Dependency Review

No Go module dependency version changes were detected in the provided diff. The only changes in go.mod files are updates to the Go toolchain version:

• go 1.25.1 -> go 1.25.5 (in both root and syntax modules)

Because no module dependencies changed, there are no dependency-specific code changes to review.

Notes

• Go toolchain was bumped from 1.25.1 to 1.25.5. This is a patch update and typically contains bug/security fixes. It should not require code changes, but you may want to review Go 1.25.2–1.25.5 release notes for any relevant runtime or compiler fixes.
• Build infrastructure was updated (e.g., grafana/alloy-build-image v0.1.22 -> v0.1.23 and golang base images 1.25.1 -> 1.25.5) in Dockerfiles and GitHub Actions. These are outside the scope of Go module dependency review.