Fix/close-issue-reason formatting in stale-issue.yml

[just1and0]

Update the close issue reason on the stale issue action.

Hey there! So you want to contribute to FirebaseUI? Before you file this pull request, follow these steps:

• Read the contribution guidelines.
• If this has been discussed in an issue, make sure to mention the issue number here. If not, go file an issue about this to make sure this is a desirable change.
• If this is a new feature please co-ordinate with someone on FirebaseUI-Android to make sure that we can implement this on both platforms and maintain feature parity.

[gemini-code-assist]

Note

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