gnu: Remove python-typing-extensions-next.

* gnu/packages/python-xyz.scm (python-typing-extensions-next): Delete variable.

gnu/packages/protobuf.scm

@@ -354,7 +354,7 @@ any memory-restricted system.")
      (list python-grpc-stubs
            python-grpcio-tools
            python-pytest
-           python-typing-extensions-next))
+           python-typing-extensions))
     (propagated-inputs
      (list protobuf
            python-protobuf

gnu/packages/python-xyz.scm

@@ -22683,21 +22683,6 @@ Included are implementations of:
 @end enumerate\n")
     (license license:psfl)))
 
-(define-public python-typing-extensions-next
-  (package
-    (inherit python-typing-extensions)
-    (name "python-typing-extensions")
-    (version "4.2.0")
-    (source (origin
-              (method git-fetch)
-              (uri (git-reference
-                    (url "https://github.com/python/typing")
-                    (commit version)))
-              (file-name (git-file-name name version))
-              (sha256
-               (base32
-                "1bbry1rg7q5ppkgzdk4nwl7q1w8bbhajm4q68wb9dm6rf7hg1023"))))))
-
 (define-public bpython
   (package
     (name "bpython")