Release 1.13.0

[mayeut]

In order to create a new release the following items should probably be completed, closed or postponed

• feat: use 1.13.0 from Kitware fork #305
• break: drop Python 3.7, manylinux2010 & musllinux_1_1 #310
  The new release is IMHO a good time to do this. A decision should be made whether to include, tweak or just post-pone
• feat: use a manylinux_2_31 compatible image for riscv64 #312
  The default manylinux target for riscv64 is quite recent, maybe it makes sense to target something older for a base tool like ninja. A decision should be made whether to include, tweak, post-pone or close.