fix: updatecli to change go_version only (#35180)

.ci/bump-golang.yml

@@ -19,12 +19,12 @@ actions:
     kind: github/pullrequest
     scmid: githubConfig
     sourceid: latestGoVersion
+    title: '[Automation] Bump Golang version to {{ source "latestGoVersion" }}'
     spec:
       automerge: false
       labels:
         - dependencies
         - backport-skip
-      title: '[Automation] Bump Golang version to {{ source "latestGoVersion" }}'
       description: |
         It requires the version to be bumped first in golang-crossbuild project, then a new release will be added to:
         https://github.com/elastic/golang-crossbuild/releases/tag/v{{ source "latestGoVersion" }}.
@@ -110,9 +110,9 @@ targets:
     scmid: githubConfig
     kind: file
     spec:
-      content: '{{ source "latestGoVersion" }}'
+      content: ':go-version: {{ source "latestGoVersion" }}'
       file: libbeat/docs/version.asciidoc
-      matchpattern: '\d+.\d+.\d+'
+      matchpattern: ':go-version: \d+.\d+.\d+'
   update-dockerfiles:
     name: "Update from dockerfiles"
     sourceid: latestGoVersion