python3-babel: upgrade 2.14.0 -> 2.15.0

python3-babel: upgrade 2.14.0 -> 2.15.0

* Override S and PYPI_SRC_URI as upstream tarball is now "babel"
  instead of "Babel", but we still need PYPI_PACKAGE to be "Babel"
  for the upstream version check to work.

What's Changed
* Drop support for Python 3.7 (EOL since June 2023) by @akx in #1048
* Upgrade GitHub Actions by @cclauss in #1054
* Improve .po IO by @akx in #1068
* Use CLDR 44 by @akx in #1071
* Allow alternative space characters as group separator when parsing
  numbers by @ronnix in #1007
* Include Unicode license in locale-data and in documentation by @akx
  in #1074
* Encode support for the "fall back to short format" logic for time
  delta formatting by @akx in #1075
* Prepare for 2.15.0 release by @akx in #1079

https://github.com/python-babel/babel/compare/v2.14.0...v2.15.0

License-Update: copyright years

Signed-off-by: Tim Orling <tim.orling@konsulko.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>