Remove cocotb_wrapper.py dependency on cocotb

This change allows the user to specify his installation of cocotb
and prevents circular includes when the rule is imported in other
repositories.

However, with this change user has to explicitely add cocotb to the list of
dependencies in the cocotb_test rule.

Internal-tag: [#46586]
Signed-off-by: Robert Winkler <[email protected]>

Author: rw1nkler

cocotb/BUILD

@@ -20,5 +20,5 @@ py_binary(
     python_version = "PY3",
     srcs_version = "PY3",
     visibility = ["//visibility:public"],
-    deps = [requirement("cocotb")],
+    deps = [],
 )