Remove Python 2 support from some third-party distributions (#7466)

Co-authored-by: Alex Waygood <[email protected]>

Author: srittau

CONTRIBUTING.md

@@ -126,10 +126,6 @@ contains the following:
 * `METADATA.toml`, describing the package. See below for details.
 * Stubs (i.e. `*.pyi` files) for packages and modules that are shipped in the
   source distribution.
-* If the stubs are either Python 2-only, or if the Python 2 and Python 3 stubs
-  are separate, the Python 2 stubs are put in a `@python2` subdirectory.
-  Stubs outside `@python2` are always used with Python 3,
-  and also with Python 2 if `python2 = true` is set in `METADATA.toml` (see below).
 * (Rarely) some docs specific to a given type stub package in `README` file.
 
 When a third party stub is added or

stubs/boto/METADATA.toml

@@ -1,3 +1,2 @@
 version = "2.49.*"
-python2 = true
 requires = ["types-six"]

stubs/cryptography/METADATA.toml

@@ -1,4 +1,2 @@
 version = "3.3.*"
-python2 = true
-requires = ["types-enum34", "types-ipaddress"]
 obsolete_since = "3.4.4"

stubs/enum34/@python2/enum.pyi

@@ -1,3 +1,2 @@
 version = "2.8.*"
-python2 = true
 requires = ["types-cryptography"]

stubs/enum34/METADATA.toml

@@ -1,3 +1,2 @@
 version = "0.2.*"
-python2 = true
 requires = ["types-paramiko"]

stubs/ipaddress/@python2/ipaddress.pyi

@@ -1,3 +1 @@
 version = "7.0.*"
-python2 = true
-requires = ["types-enum34"]