Merge pull request scipy#22181 from tylerjereddy/treddy_prep_scipy_1.15.0rc3

REL: set 1.15.0rc3 unreleased

Author: rgommers

pyproject.toml

@@ -43,7 +43,7 @@ requires = [
 
 [project]
 name = "scipy"
-version = "1.15.0rc2"
+version = "1.15.0rc3.dev0"
 # TODO: add `license-files` once PEP 639 is accepted (see meson-python#88)
 #       at that point, no longer include them in `py3.install_sources()`
 license = { file = "LICENSE.txt" }