Replace last pose if only orientation differs in Navfn (backport #5490)

[mergify]

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Basic Info

Info	Please fill out this column
Ticket(s) this addresses	#4755 (comment)
Primary OS tested on	(Ubuntu, MacOS, Windows)
Robotic platform tested on	(Steve's Robot, gazebo simulation of Tally, hardware turtlebot)
Does this PR contain AI generated software?	(No; Yes and it is marked inline in the code)
Was this PR description generated by AI software?	Out of respect for maintainers, AI for human-to-human communications are banned

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Description of contribution in a few bullet points

Description of documentation updates required from your changes

Description of how this change was tested

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Future work that may be required in bullet points

For Maintainers:

• Check that any new parameters added are updated in docs.nav2.org
• Check that any significant change is added to the migration guide
• Check that any new features OR changes to existing behaviors are reflected in the tuning guide
• Check that any new functions have Doxygen added
• Check that any new features have test coverage
• Check that any new plugins is added to the plugins page
• If BT Node, Additionally: add to BT's XML index of nodes for groot, BT package's readme table, and BT library lists
• Should this be backported to current distributions? If so, tag with backport-*.

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This is an automatic backport of pull request #5490 done by [Mergify](https://mergify.com).

[mergify]

@mergify[bot], all pull requests must be targeted towards the main development branch.
Once merged into main, it is possible to backport to @kilted, but it must be in main
to have these changes reflected into new distributions.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

Files with missing lines	Coverage Δ
nav2_navfn_planner/src/navfn_planner.cpp	95.45% <100.00%> (-0.43%)	⬇️

... and 5 files with indirect coverage changes

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