Resolve stray __pydantic_var__ Pydantic V2 issues in integrations/packs

[nerdai]

Description

Some missed integrations and packs were missed when resolving __pydantic_var__ errors which can be resolved by moving the super().__init__(...) call before any private vars are set within a custom __init__() function of a BaseModel subclass.

Fixes # (issue)

Closes #15609

Version Bump?

Did I bump the version in the pyproject.toml file of the package I am updating? (Except for the llama-index-core package)

• Yes
• No

Type of Change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• Added new unit/integration tests
• Added new notebook (that tests end-to-end)
• I stared at the code and made sure it makes sense

[logan-markewich]

Thanks a ton!! 🥰