[Merged by Bors] - refactor(Geometry/Euclidean): use orthogonalProjectionSpan more

[jsm28]

Make more use of orthogonalProjectionSpan in
Mathlib.Geometry.Euclidean.Projection and
Mathlib.Geometry.Euclidean.SignedDist. Split out from #23752.

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[github-actions]

PR summary 3d041b4c90

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

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Declarations diff

No declarations were harmed in the making of this PR! 🐙

You can run this locally as follows

## summary with just the declaration names:
./scripts/declarations_diff.sh <optional_commit>

## more verbose report:
./scripts/declarations_diff.sh long <optional_commit>

The doc-module for script/declarations_diff.sh contains some details about this script.

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No changes to technical debt.

You can run this locally as

./scripts/technical-debt-metrics.sh pr_summary

• The relative value is the weighted sum of the differences with weight given by the inverse of the current value of the statistic.
• The absolute value is the relative value divided by the total sum of the inverses of the current values (i.e. the weighted average of the differences).

[eric-wieser]

Arguably this lemma should be renamed to use orthogonalProjectionSpan, though of course then you'll need a deprecation.

bors d+

[eric-wieser]

(though if this will be changed again to use altitude, then fine to leave as is for now)

[jsm28]

Yes, I expect this to change to be about altitudeFoot (and thus move to go alongside that definition) (and I'm also doubtful of the need for deprecations for such recently added lemmas).

bors r+

[mathlib-bors]

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[mathlib-bors]

Pull request successfully merged into master.

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