ci: have props-bot post merge commit trailers alongside the SVN line

[josephfusco]

Switches props-bot to format: all so the comment carries core's Co-authored-by merge commit block alongside the Props line the release comment and readme.txt Contributors sync are generated from.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 56.94%. Comparing base (d0612be) to head (836b832).

Additional details and impacted files

@@            Coverage Diff            @@
##               main      #66   +/-   ##
=========================================
  Coverage     56.94%   56.94%           
  Complexity       42       42           
=========================================
  Files            11       11           
  Lines           367      367           
=========================================
  Hits            209      209           
  Misses          158      158           

Flag	Coverage Δ
multisite	56.94% <ø> (ø)
phpunit	52.47% <ø> (ø)

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[github-actions]

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

Core Committers: Use this line as a base for the props when committing in SVN:

Props joefusco.

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