Try fixing more Sphinx refs which fail only on Ubuntu...

docs/validate.rst

@@ -16,7 +16,7 @@ The Basics
 ----------
 
 The simplest way to validate an instance under a given schema is to use the
-:func:`validate` function.
+`validate <jsonschema.validators.validate>` function.
 
 .. autofunction:: validate
     :noindex:

jsonschema/protocols.py

@@ -29,6 +29,7 @@
 # but use `jsonschema` for any types which will otherwise not be resolvable
 if TYPE_CHECKING:
     import jsonschema
+    import jsonschema.validators
 
 from jsonschema.exceptions import ValidationError
 
@@ -107,7 +108,7 @@ class Validator(Protocol):
     def __init__(
         self,
         schema: Mapping | bool,
-        resolver: jsonschema.RefResolver | None = None,
+        resolver: jsonschema.validators.RefResolver | None = None,
         format_checker: jsonschema.FormatChecker | None = None,
     ) -> None:
         ...

jsonschema/validators.py

@@ -1060,9 +1060,9 @@ def validate(instance, schema, cls=None, *args, **kwargs):
             ...
         ValidationError: [2, 3, 4] is too long
 
-    :func:`validate` will first verify that the provided schema is
-    itself valid, since not doing so can lead to less obvious error
-    messages and fail in less obvious or consistent ways.
+    :func:`~jsonschema.validators.validate` will first verify that the
+    provided schema is itself valid, since not doing so can lead to less
+    obvious error messages and fail in less obvious or consistent ways.
 
     If you know you have a valid schema already, especially
     if you intend to validate multiple instances with