📖 Fix typo in branch protections details

[martincostello]

What kind of change does this PR introduce?

Fix typo in branch protections details message.

• PR title follows the guidelines defined in our pull request documentation

What is the current behavior?

Messages such as the following are emitted in scorecard reports:

Warn: 'stale review dismissal' is disable on branch 'main'

What is the new behavior (if this is a feature change)?**

Grammar in message is fixed to use the correct text:

- Warn: 'stale review dismissal' is disable on branch 'main'
+ Warn: 'stale review dismissal' is disabled on branch 'main'

• Tests for the changes have been added (for bug fixes/features)

Which issue(s) this PR fixes

NONE

Special notes for your reviewer

Does this PR introduce a user-facing change?

Fix typo in branch protections details.

[spencerschrock]

Thanks.

(Note: the e2e failure is something else and will need to be resolved by maintainers separately in a different PR)