[1.8] Pin docs to 7.15 stack version

[bmorelli25]

This pins an older version of the docs to the stack so we don't ever have to worry about broken links again.

[apmmachine]

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• Start Time: 2022-01-24T11:42:21.395+0000

• Duration: 4 min 38 sec

• Commit: 669e3ad

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