Add Dev image for AC 2.1.0-3

[kaxil]

This commit/PR adds a nightly build for AC 2.1.0-3

https://github.com/astronomer/airflow/commits/v2-1-0/

Changelog

Astronomer Certified 2.1.0-3.dev, TBC

Bugfixes

• Avoid recursing too deep when redacting logs (#16491) (commit)
• Switch to built-in data structures in SecretsMasker (#16424) (commit)
• Don't fail to log if we can't redact something (#16118) (commit)
• Don't show stale Serialized DAGs if they are deleted in DB (#16368) (commit)
• fix: change graph focus to top of view instead of center (#16484) (commit)
• Fix Orphaned tasks stuck in CeleryExecutor as running (#16550) (commit)
• Redact conn secrets in webserver logs (#16579) (commit)
• Don't crash attempting to mask secrets in dict with non-string keys (#16601) (commit)
• Fix Dag Details start date bug (#16206) (commit)
• Tree View UI for larger DAGs & more consistent spacing in Tree View (#16522) (commit)
• Make task ID on legend have enough width and width of line chart to be 100%. (#15915) (commit)
• Fix normalize-url vulnerability (#16375) (commit)
• Clean Markdown with dedent to respect indents (#16414) (commit)
• add num_runs query param for tree refresh (#16437) (commit)
• set max tree width to 1200px (#16067) (commit)
• Exclude yarn.lock from built Python wheel file (#16577) (commit)
• Bump version to 2.1.0.dev1+astro.3 (commit)
• Add passphrase and private_key to default sensitive fileld names (#16392) (commit)
• Dockerfile: Add constraint for installed Airflow version (Add constraint for installed Airflow version #274) (commit)
• Dockerfile: Upgrade Fab Security manager to 1.6.0 (upgrade fab sec manager to 1.6.0 #272) (commit)

[ernest-kr]

LGTM