fix(ingestion): Restrict python to <=3.9.9

[treff7es]

Restrict python to <=3.9.9 due to looker-open-source/sdk-codegen#944 causes build failure

Checklist

• The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• Links to related issues (if applicable)
• Tests for the changes have been added/updated (if applicable)
• Docs related to the changes have been added/updated (if applicable)

[github-actions]

Unit Test Results (build & test)

  45 files  ±0    45 suites  ±0   15m 28s ⏱️ + 4m 8s
505 tests ±0  449 ✔️ ±0  56 💤 ±0  0 ❌ ±0 

Results for commit 6f6eec0. ± Comparison against base commit f2e2a4d.

♻️ This comment has been updated with latest results.

[github-actions]

Unit Test Results (metadata ingestion)

       5 files  ±  0         5 suites  ±0   39m 26s ⏱️ + 3m 58s
   274 tests  -   2     273 ✔️ +  7    0 💤  - 6  1 ❌  - 1 
1 261 runs  +14  1 232 ✔️ +27  28 💤  - 6  1 ❌  - 3 

For more details on these failures, see this check.

Results for commit 6f6eec0. ± Comparison against base commit f2e2a4d.

This pull request removes 2 tests.

tests.integration.looker.test_looker
tests.integration.lookml.test_lookml

♻️ This comment has been updated with latest results.

[shirshanka]

LGTM! Merging before CI turns fully green.