4.6: Fix composer.json

[adriendupuis]

Question	Answer
JIRA Ticket
Versions	4.6
Edition

Fix missing comma.

Found while testing #2723

Error: "./composer.json" does not contain valid JSON
Parse error on line 68:
...le": "^4.0"        "ibexa/connector-dam...
---------------------^
Expected one of: 'EOF', '}', ':', ',', ']'

Probably a cherry-pick issue in bbdec06#diff-d2ab9925cad7eac58e0ff4cc0d251a937ecf49e4b6bf57f8b95aab76648a9d34R69

Checklist

• Text renders correctly
• Text has been checked with vale
• Description metadata is up to date
• Redirects cover removed/moved pages
• Code samples are working
• PHP code samples have been fixed with PHP CS fixer
• Added link to this PR in relevant JIRA ticket or code PR

[github-actions]

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