Spatial_search: Duplicate point handling

[soesau]

Summary of Changes

stop splitting nodes if the contained points are only duplicates

Release Management

• Affected package(s): dD Spatial Searching

[sloriot]

Successfully tested in CGAL-6.1-Ic-78

[sloriot]

Are you planning any more changes or shall we merge the branch?

[soesau]

Not yet.

[github-actions]

This pull-request was previously marked with the label Tested, but has been modified with new commits. That label has been removed.

[soesau]

/build:v0

[github-actions]

There was an error while building the doc:

/home/runner/work/cgal/cgal/Documentation/doc/scripts/html_output_post_processing.py:187: SyntaxWarning: invalid escape sequence '\.'
  re_pkg_index=re.compile("\.\./([A-Z_a-z0-9]+)/index\.html")
/home/runner/work/cgal/cgal/Documentation/doc/scripts/html_output_post_processing.py:251: SyntaxWarning: invalid escape sequence '\('
  re_replace_in_file("operator<<\(\)", "operator&lt;&lt;()", f)
/home/runner/work/cgal/cgal/Documentation/doc/scripts/html_output_post_processing.py:322: SyntaxWarning: invalid escape sequence '\['
  re_replace_in_file('^.*\[ "Concepts",.*$', '', fn)
/home/runner/work/cgal/cgal/Documentation/doc/scripts/html_output_post_processing.py:332: SyntaxWarning: invalid escape sequence '\['
  re_replace_in_file('\[external\]', '', os.path.join('Manual','annotated.html'))

https://github.com/CGAL/cgal/actions/runs/13411027822