Add a linting phase to the CI pipeline

### Story

As developers, we should collaboratively ensure that all new code is properly linted before merging it into the `main` or `develop` branch.

### Overview

Objective: Create a github action that checks new PRs for linter errors before merging it into `develop` or `main`.

We are going to do this instead of using git pre-comit hooks.
- In my personal opinion, pre-commit hooks are slow and can be disruptive to a developers workflow. It can take up to 3-5 seconds just to complete a commit.
- If a developer already has eslint extension on vscode (or other personal linter) set to format code on save, the pre-commit approach is redundant.
- Instead, we should check for linter errors at the Pull Request step. If this check catches any errors, it can remind the developer to run the linters before merging the PR.
- context: needed to remind dev to lint their PR here: #668

### Action Items

- [ ] Create a github action that checks frontend PRs for eslint errors before merging it into `develop` or `main`.
- [ ] Create a github action that checks backend PRs for python linting errors before merging it into `develop` or `main`.

These two tasks can be separated into two different PRs for convenience.

### Resources/Instructions

- [Resources](https://hackforla.github.io/CivicTechJobs/resources/)

Linting docs:
- https://hackforla.github.io/CivicTechJobs/developer/backend/#linting-the-backend
- https://hackforla.github.io/CivicTechJobs/developer/frontend/#eslint-configuration-documentation-for-frontend-developers