[BUG] array node sub node control flow inheritance

[pvditt]

Tracking issue

Why are the changes needed?

Array node increments workflow parallelism from the parent node. Right now, the same control flow that tracks parallelism for the workflow is passed down to subnodes allowing subnodes to bump the workflow parallelism which could lead to a double counting of nodes getting evaluated in a workflow.

If/when ArrayNode supports subworkflows or dynamics then we can pass back in the parent control flow.

What changes were proposed in this pull request?

Init a new control flow when creating the exec context for array node subnodes

How was this patch tested?

Ran a few workflows locally

Setup process

Screenshots

Check all the applicable boxes

• [ ] I updated the documentation accordingly.
• [x] All new and existing tests passed.
• [x] All commits are signed-off.

Related PRs

Docs link

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 61.01%. Comparing base (8805613) to head (a00afea). Report is 447 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5505      +/-   ##
==========================================
+ Coverage   60.15%   61.01%   +0.85%     
==========================================
  Files         646      794     +148     
  Lines       45883    51445    +5562     
==========================================
+ Hits        27603    31389    +3786     
- Misses      15672    17164    +1492     
- Partials     2608     2892     +284     

Flag	Coverage Δ
unittests-datacatalog	69.31% <ø> (ø)
unittests-flyteadmin	58.73% <ø> (ø)
unittests-flytecopilot	17.79% <ø> (ø)
unittests-flytectl	68.03% <ø> (?)
unittests-flyteidl	79.04% <ø> (ø)
unittests-flyteplugins	61.85% <ø> (ø)
unittests-flytepropeller	57.31% <100.00%> (+<0.01%)	:arrow_up:
unittests-flytestdlib	65.82% <ø> (+0.02%)	:arrow_up:

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[pvditt]

@hamersaw This would mess with the node + task count. I'll look back into this.

[eapolinario]

Cleaning stale PRs. Please reopen if you wan to discuss this further.