Support google-cloud-tasks>=2.0.0

[mik-laj]

Part of: #12116

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[turbaszek]

Not a strong opinion, but I think doing this before function invocation may increase readability, WDYT?

[mik-laj]

I am not sure about that. For full readability this would require creating a new variable name, as modifying the parameter content may be ambiguous as some languages have special behavior. Luckily not in Python, but this can still arouse mixed feelings among polyglots, including mine. The new variable in this case would complicate the code unnecessarily.

[github-actions]

The PR most likely needs to run full matrix of tests because it modifies parts of the core of Airflow. However, committers might decide to merge it quickly and take the risk. If they don't merge it quickly - please rebase it to the latest master at your convenience, or amend the last commit of the PR, and push it with --force-with-lease.