[AIRFLOW-XXX] Ignore FAB's db tables when auto-generating migrations

[ashb]

Jira

• No Jira

Description

• Make alembic revision --autogenerate ignore any table starting with
  ab_ as that is what Flask-AppBuilder uses and we don't manage those tables.

[codecov-io]

Codecov Report

Merging #6221 into master will decrease coverage by <.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #6221      +/-   ##
==========================================
- Coverage   80.02%   80.02%   -0.01%     
==========================================
  Files         610      610              
  Lines       35176    35176              
==========================================
- Hits        28151    28148       -3     
- Misses       7025     7028       +3

Impacted Files	Coverage Δ
airflow/contrib/operators/ssh_operator.py	82.5% <0%> (-1.25%)	⬇️
airflow/utils/dag_processing.py	56.55% <0%> (-0.35%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 844bbad...f4232d8. Read the comment docs.