v3.3

Some highlights:

• Min Python version is now 3.8!
• Components can now use a package_install settings to specify if they should be installed from pip, github or URL when cobaya-install is run.
• MCMC: added tempered sampling.
• Planck:
  • Replaced default planck_2018_lowl.EE and planck_2018_low.TT with native versions, and using GitHub-hosted clik.
  • Added latest PR4 NPIPE fully-Python likelihoods