Fix issue template labels (#21686)

Issue forms should only reference labels that exist in the repository so
new reports receive the intended automatic labels.

This updates the CLI issue form to stop applying the missing `needs
triage` label, and changes the documentation issue form from `docs` to
the existing `documentation` label.

Fixes #21158

.github/ISSUE_TEMPLATE/3-cli.yml

@@ -2,7 +2,6 @@ name: 💻 CLI Bug
 description: Report an issue in the Codex CLI
 labels:
   - bug
-  - needs triage
 body:
   - type: markdown
     attributes:

.github/ISSUE_TEMPLATE/6-docs-issue.yml

@@ -1,6 +1,6 @@
 name: 📗 Documentation Issue
 description: Tell us if there is missing or incorrect documentation
-labels: [docs]
+labels: [documentation]
 body:
   - type: markdown
     attributes:
@@ -24,4 +24,4 @@ body:
   - type: textarea
     attributes:
       label: Where did you find it?
-      description: If possible, please provide the URL(s) where you found this issue.
+      description: If possible, please provide the URL(s) where you found this issue.