Remove duplicated by (#14945)

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## DESCRIBE YOUR PR
*Tell us what you're changing and why. If your PR **resolves an issue**,
please link it so it closes automatically.*

Some parts of the documentation were using `by by`, I replaced themy by
just `by`.

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## PRE-MERGE CHECKLIST

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Author: lucas-zimerman

develop-docs/sdk/telemetry/client-reports.mdx

@@ -111,7 +111,7 @@ that SDKs send these under normal operation:
 : _List of outcome objects_ \{`reason`, `category`, `quantity`\}
 
 These function like `discarded_events` but identify events that were rate limited,
-filtered or filtered by by dynamic sampling _at a relay_. Client SDKs must never
+filtered or filtered by dynamic sampling _at a relay_. Client SDKs must never
 emit these _unless_ they are operating as a relay. The reason codes for these
 need to match the reason codes that relay would emit directly to Sentry.
 

docs/platforms/javascript/common/user-feedback/configuration/index.mdx

@@ -164,7 +164,7 @@ The following values are only available as CSS variables, and apply to both dark
 | `--inset`       | `auto 0 0 auto`                                    | By default, the widget has fixed position, and is in the bottom right corner.                                                                                                 |
 | `--page-margin` | `16px`                                             | The margin from the edge of the screen that the widget should be positioned. This also accepts shorthand values like `10px 20px 30px 10px` for top/right/bottom/left margins. |
 
-Colors can be customized by by defining CSS variables that override the default values, or by passing `themeLight` and/or `themeDark` to `feedbackIntegration({})`.
+Colors can be customized by defining CSS variables that override the default values, or by passing `themeLight` and/or `themeDark` to `feedbackIntegration({})`.
 
 | CSS Variable          | Configuration Key  | Default Light Mode                        | Default Dark Mode                         | Description                                                                                             |
 | --------------------- | ------------------ | ----------------------------------------- | ----------------------------------------- | ------------------------------------------------------------------------------------------------------- |