[python-modules-kit] Dismiss virtual/typing from the tree

The package net-wireless/crda needs `dev-python/m2crypto` as dependency that depends on virtual/python-typing.

The package virtual/python-typing inject dev-python/typing that is a backport of the standard library typing module to Python versions older than 3.5. Considering that we have py3.9 we can drop this package from the tree.

```
$> grep virtual/python-typing /var/git/meta-repo/kits/* -r -l
/var/git/meta-repo/kits/dev-kit/dev-util/vint/vint-0.3.18.ebuild
/var/git/meta-repo/kits/dev-kit/dev-util/vint/vint-0.3.19.ebuild
/var/git/meta-repo/kits/dev-kit/metadata/md5-cache/dev-util/vint-0.3.18
/var/git/meta-repo/kits/dev-kit/metadata/md5-cache/dev-util/vint-0.3.19
/var/git/meta-repo/kits/dev-kit/metadata/md5-cache/dev-db/mongodb-3.6.23
/var/git/meta-repo/kits/dev-kit/metadata/md5-cache/dev-db/mongodb-4.0.28
/var/git/meta-repo/kits/dev-kit/dev-db/mongodb/mongodb-3.6.23.ebuild
/var/git/meta-repo/kits/dev-kit/dev-db/mongodb/mongodb-4.0.28.ebuild
/var/git/meta-repo/kits/dev-kit/dev-db/mongodb/templates/mongodb-3.6.tmpl
/var/git/meta-repo/kits/dev-kit/dev-db/mongodb/templates/mongodb-4.0.tmpl
/var/git/meta-repo/kits/net-kit/net-misc/gns3-server/gns3-server-2.1.3-r4.ebuild
/var/git/meta-repo/kits/net-kit/metadata/md5-cache/net-misc/gns3-server-2.1.3-r4
/var/git/meta-repo/kits/python-modules-kit/.git/index
/var/git/meta-repo/kits/python-modules-kit/dev-python/m2crypto/m2crypto-0.43.0.ebuild
/var/git/meta-repo/kits/python-modules-kit/metadata/md5-cache/dev-python/m2crypto-0.43.0
```

Start by rerunning the grep for virtual/python-typing across the listed kits, then inspect the matching ebuilds and templates, especially the m2crypto package in python-modules-kit. Remove the obsolete references from the affected package definitions and verify that the tree no longer contains unintended virtual/python-typing dependencies.

Written by the indexing model from the issue text.