ref: Remove helpers left over from EventScrubber removal (#8158)

### Description

Removes two helpers that only `EventScrubber` used:

- `iter_event_frames()` in `sentry_sdk/utils.py`
- `AnnotatedValue.substituted_because_contains_sensitive_data()` in
`sentry_sdk/_types.py`

#7772 ("Remove `EventScrubber` and the `event_scrubber` option") deleted
`sentry_sdk/scrubber.py`, which held the only call to each of them:
frame-vars scrubbing called `iter_event_frames(event)`, and denylisted
keys were replaced with
`AnnotatedValue.substituted_because_contains_sensitive_data()`. Both
helpers were left behind.

**Evidence**
- On `major/3.0`, `git grep -w` for each name matches only its
definition. There are no callers in `sentry_sdk`, `tests`, `scripts` or
`docs`.
- No open PR touches either one.

`iter_event_stacktraces()` (used by `handle_in_app`) and
`SENSITIVE_DATA_SUBSTITUTE` (used by the data-collection filtering and
several integrations) are still used, so they stay.

On `master`, `EventScrubber` still uses both helpers, so this only
applies to `major/3.0`. `iter_event_frames` could be imported from
`sentry_sdk.utils`, but it isn't documented anywhere, and `major/3.0` is
already a breaking release.

#### Issues
n/a

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via **Ivana Kellyer**.
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Co-authored-by: sentry-junior[bot] <264270552+sentry-junior[bot]@users.noreply.github.com>

Author: sentry-junior[bot]

sentry_sdk/_types.py

@@ -112,21 +112,6 @@ def substituted_because_over_size_limit(
             },
         )
 
-    @classmethod
-    def substituted_because_contains_sensitive_data(cls) -> "AnnotatedValue":
-        """The actual value was removed because it contained sensitive information."""
-        return AnnotatedValue(
-            value=SENSITIVE_DATA_SUBSTITUTE,
-            metadata={
-                "rem": [  # Remark
-                    [
-                        "!config",  # Because of SDK configuration (in this case the config is the hard coded removal of certain django cookies)
-                        "s",  # The fields original value was substituted
-                    ]
-                ]
-            },
-        )
-
 
 T = TypeVar("T")
 Annotated = Union[AnnotatedValue, T]

sentry_sdk/utils.py

@@ -986,15 +986,6 @@ def iter_event_stacktraces(event: "Event") -> "Iterator[Annotated[Dict[str, Any]
                 yield exception["stacktrace"]
 
 
-def iter_event_frames(event: "Event") -> "Iterator[Dict[str, Any]]":
-    for stacktrace in iter_event_stacktraces(event):
-        if isinstance(stacktrace, AnnotatedValue):
-            stacktrace = stacktrace.value or {}
-
-        for frame in stacktrace.get("frames") or ():
-            yield frame
-
-
 def handle_in_app(
     event: "Event",
     in_app_exclude: "Optional[List[str]]" = None,