Add click compatibility for 8.1.x vs 8.2.x

`get_metavar` changed in 8.2.0 and has a workaround covered in `click`
docs, which is now applied here.

Author: sirosen

piptools/_internal/_cli/_param_types.py

@@ -1,12 +1,40 @@
 from __future__ import annotations
 
+import functools
+import typing as _t
+
 import click
 
 from . import _parsed_param_types
 
+F = _t.TypeVar("F", bound=_t.Callable[..., _t.Any])
+
+
+def _add_ctx_arg(f: F) -> F:
+    """
+    Make ``ParamType`` methods compatible with various click versions, as documented
+    in the click docs here:
+    https://click.palletsprojects.com/en/stable/support-multiple-versions/
+    """
+
+    @functools.wraps(f)
+    def wrapper(*args: _t.Any, **kwargs: _t.Any) -> _t.Any:
+        # NOTE: this check is skipped in coverage as it requires a lower `click` version
+        # NOTE: once we have a coverage plugin for library version pragmas, we can make
+        # NOTE: this do the appropriate dispatch
+        if "ctx" not in kwargs:  # pragma: no cover
+            kwargs["ctx"] = click.get_current_context(silent=True)
+
+        return f(*args, **kwargs)
+
+    return wrapper  # type: ignore[return-value]
+
 
 class DependencyGroupParamType(click.ParamType):
-    def get_metavar(self, param: click.Parameter) -> str:
+    @_add_ctx_arg
+    def get_metavar(  # type: ignore[override]
+        self, param: click.Parameter, ctx: click.Context
+    ) -> str:
         return "[pyproject-path:]groupname"
 
     def convert(