Merge branch '199695-vale-first-person' into 'master'

Docs: Add Vale tests for first-person pronouns

Closes #199695

See merge request gitlab-org/gitlab!25928

doc/.linting/vale/styles/gitlab/FirstPerson.yml

+# Checks for use of first person pronouns.
+#
+# For a list of all options, see https://errata-ai.github.io/vale/styles/
+extends: existence
+message: '`%s` is a first-person pronoun. Use second- or third-person pronouns (like we, you, us, one) instead.'
+level: warning
+ignorecase: true
+link: https://docs.gitlab.com/ee/development/documentation/styleguide.html#language
+tokens:
+  - '\bI[ ,;:?!"]|\bI\x27.{1,2}'
+  - me
+  - myself
+  - mine