chore(deps): update dependency go to v1.25.5 (#346)

| datasource     | package | from   | to     |
| -------------- | ------- | ------ | ------ |
| golang-version | go      | 1.25.4 | 1.25.5 |

Signed-off-by: renovate-sh-app[bot] <219655108+renovate-sh-app[bot]@users.noreply.github.com>
Co-authored-by: renovate-sh-app[bot] <219655108+renovate-sh-app[bot]@users.noreply.github.com>

Author: renovate-sh-app[bot]

go.mod

@@ -2,7 +2,7 @@ module github.com/grafana/flagger-k6-webhook
 
 go 1.24.0
 
-toolchain go1.25.4
+toolchain go1.25.5
 
 require (
 	github.com/golang/mock v1.6.0