Fix "implicit any" Typescript errors to prepare for Typescript 5.5

[rmunn]

Fixes #1800

Description

We currently have suppressImplicitAnyIndexErrors in our tsconfig.json since we have a lot of implicit any types scattered throughout our code. That option will be going away in Typescript 5.5, so we need to fix them now so that we can continue to upgrade Typescript in the future (5.5 is currently in beta).

Screenshots

No behavioral changes.

Checklist

• [X] I have labeled my PR with: bug, feature, engineering, security fix or testing
• [X] I have performed a self-review of my own code
• [X] I have reviewed the title & description of this PR which I will use as the squashed PR commit message
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] I have enabled auto-merge (optional)

Testing

Testers, use the following instructions against our staging environment. Post your findings as a comment and include any meaningful screenshots, etc.

• Run make, make sure site still loads.
• Check that there aren't more Typescript errors showing up in VS Code.

[github-actions[bot]]

Unit Test Results

362 tests   362 :white_check_mark:  13s :stopwatch:  37 suites    0 :zzz:   1 files      0 :x:

Results for commit c92e2e69.