Enable Lint check

[ljubon]

Checklist before submitting

• Did you read the contributing guide?
• Did you update the docs?
• Did you write any tests to validate this change?

Description

The goal of this change is to enable linting as required check for the CI
example run: https://github.com/ljubon/spark-dgraph-connector/actions/runs/6946230885/job/18897234201

Fixes # (issue).

Review process for approval

1. All tests and other checks must succeed.
2. At least one core contributors must review and approve.
3. If a core contributor requests changes, they must be addressed.

[EnricoMi]

I'd prefer to do this the same way we did in G-Research/spark-extension#201 and G-Research/spark-extension#212.

[github-actions]

Test Results

0 files   -  2 996  0 suites   - 2 996   0s ⏱️ - 51m 43s
0 tests  -    485  0 ✅  -    485  0 💤 ±0  0 ❌ ±0 
0 runs   - 42 988  0 ✅  - 42 988  0 💤 ±0  0 ❌ ±0 

Results for commit 76ee286. ± Comparison against base commit d7efaad.

[ljubon]

I'd prefer to do this the same way we did in G-Research/spark-extension#201 and G-Research/spark-extension#212.

In latest commit, i've applied changes from suggested PRs/commits:

• https://github.com/G-Research/spark-extension/pull/212/files
• G-Research/spark-extension@0e634c2

p.s format is not applied, so it's expected that action Linting is failing - let me know if you want me to commit to this PR formated code which will affect the files in src/