Docs: missing `]` character in database->aggregate documentation

[bduranleau-nr]

Bug Report

Hi 👋 ,

Was going through the documentation for the MongoDB PHP Library and came across this example,
which seems to result in a syntax error when taken verbatim due to a missing ] character.

If so, it looks like this is the corresponding block of code/text that needs to be updated.

Let me know if this is the incorrect place/avenue to report this.

Thanks!

Environment

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Test Script

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Expected and Actual Behavior

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Debug Log

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[alcaeus]

Thanks for reporting this, I've created #1285 to fix the issue.