Upgrade svgtypes, roxmltree and ttf-parser for broot

This MR upgrades svgtypes to v0.15.1, roxmltree to v0.20.0 and ttf-parser to v0.24.1. The upgrades are needed for some dependencies of broot (ITP #948483). Before merging it, I would like to hear from the uploaders/maintainers of some of the packages I changed if they have objections. Specifically:

• ttf-parser (cc/ @jamessan)

  • I had to add a large number of test_is_broken's in ttf-parser for the usual reason, upstream does not support testing one feature at a time (e.g. in newer versions you must explicitly select either the std or the no-std-float feature for each of the other features). On the plus side, tests now pass with the default features and with all features enabled
  • I used collapse_features since I found no reason not to
  • It looks like disable-overflow-test-unless-64-bit.patch is not needed anymore, although the relative issue has not been closed yet. If tests pass in Debian's CI as I expect them to I'm going to ask upstream to close the issue

• plotters (rdep of ttf-parser) (cc/ @jamessan @capitol)

  • I had to downgrade itertools back to 0.10 for unstable because 0.12 is still in experimental. @eamanu, who will sponsor me for broot, told me he's willing to upload directly to unstable, and I'd rather do so because to upload to experimental I'd have to change a number of dependencies for other packages (just to then change them back for unstable)

Other than this, Evgeniy Reizner changed the spelling of his name to Yevhenii Reizner in licenses, so I changed it too in multiple packages.