ajv 6.12.6 -> 8.17.1

[sarahec]

Description

1. Bumped ajv dependency from ^6.12.6 to ^8.17.1 (latest)
2. Added ajv-formats module in firebaseConfigValidate.ts to include definition for uri
3. Replaced error.dataPath with instancePath (deprecated in ajv 7, removed in ajv 8; see ajv migration notes)

Fixes #8088

Scenarios Tested

Ran npm run test. No failures. 2906 passing, 4 pending.

Sample Commands

n/a

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