Fix minor issues in opentracing (#6482)

stubs/opentracing/opentracing/mocktracer/tracer.pyi

@@ -1,4 +1,3 @@
-from ..propagation import Format
 from ..scope_manager import ScopeManager
 from ..span import Span
 from ..tracer import Tracer
@@ -6,6 +5,6 @@ from .propagator import Propagator
 
 class MockTracer(Tracer):
     def __init__(self, scope_manager: ScopeManager | None = ...) -> None: ...
-    def register_propagator(self, format: Format, propagator: Propagator) -> None: ...
+    def register_propagator(self, format: str, propagator: Propagator) -> None: ...
     def finished_spans(self) -> list[Span]: ...
     def reset(self) -> None: ...

stubs/opentracing/opentracing/scope_manager.pyi

@@ -5,4 +5,4 @@ class ScopeManager:
     def __init__(self) -> None: ...
     def activate(self, span: Span, finish_on_close: bool) -> Scope: ...
     @property
-    def active(self) -> Scope: ...
+    def active(self) -> Scope | None: ...

stubs/opentracing/opentracing/tracer.pyi

@@ -1,6 +1,5 @@
 from typing import Any, NamedTuple
 
-from .propagation import Format
 from .scope import Scope
 from .scope_manager import ScopeManager
 from .span import Span, SpanContext
@@ -30,8 +29,8 @@ class Tracer:
         start_time: float | None = ...,
         ignore_active_span: bool = ...,
     ) -> Span: ...
-    def inject(self, span_context: SpanContext, format: Format, carrier: dict[Any, Any]) -> None: ...
-    def extract(self, format: Format, carrier: dict[Any, Any]) -> SpanContext: ...
+    def inject(self, span_context: SpanContext, format: str, carrier: dict[Any, Any]) -> None: ...
+    def extract(self, format: str, carrier: dict[Any, Any]) -> SpanContext: ...
 
 class ReferenceType:
     CHILD_OF: str