Upgrade Web3.py

### User Story

https://web3py.readthedocs.io/en/stable/v5_migration.html#migrating-v4-to-v5

https://github.com/gitcoinco/web/pull/6331#issuecomment-608037602

[comment]: # (As a , I want to so that .)

### Why Is this Needed

[comment]: # (Describe the problem and why this task is needed. Provide description of the current state, what you would like to happen, and what actually happen)
*Summary*:

### Description

[comment]: # (Feature or Bug? i.e Type: Bug)
*Type*:

### Current Behavior
[comment]: # (Describe what actually happened.)

### Expected Behavior
[comment]: # (Describe what you expected to happen.)

### Definition of Done
[comment]: # (Any other information that would be useful, bullets are helpful.)

### Data Requirements
[comment]: # (How will we measure the success of this feature? What kind of tracking is needed for this feature (clicks, impressions, flag)?)

### Additional Information
[comment]: # (Any other information that would be useful, content, screenshots, etc.)