Git index version 3 support

sebastianst

Using git python to add files to an index fails at an index head assertion if the local repo is being otherwise worked on with git 2.46.0:

Lines 209 to 210 in cfadd9e

	# TODO: Handle version 3: extended data, see read-cache.c.
	assert version in (1, 2)

Is it planned to add support for version 3 soon?

I couldn't find any ticket tracking this, so apologies if this is a duplicate.