docs: Fix Solid, SolidStart, and NestJS README snippets

[nicohrubec]

Fix the Solid and SolidStart README examples to call the imported router wrapper, and remove the duplicate NestJS MonitorConfig import so the snippets use valid imports.

Closes #24548.

[sentry]

Bug: The @sentry/solid README example incorrectly calls withSentryRouterRouting as a method on the Sentry namespace, which will cause a runtime TypeError.
_{Severity: HIGH}

Suggested Fix

Update the README example to call withSentryRouterRouting(Router) directly, and ensure the import statement correctly imports it as a named export from '@sentry/solid/solidrouter'.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent. Verify if this is a real issue. If it is, propose a fix; if not, explain why it's
not valid.

Location: packages/solid/README.md#L42

Potential issue: The example code in the `@sentry/solid` README for setting up router
integration demonstrates an incorrect usage of `withSentryRouterRouting`. It shows
`Sentry.withSentryRouterRouting(Router)`, but `withSentryRouterRouting` is a named
export from the `@sentry/solid/solidrouter` module, not a property on the `Sentry`
namespace object. Users copying this code snippet will encounter a `TypeError:
Sentry.withSentryRouterRouting is not a function` at runtime, preventing the integration
from working.

_{Did we get this right? 👍 / 👎 to inform future reviews.}

[sentry]

Bug: The @sentry/nestjs README example incorrectly imports MonitorConfig from @sentry/nestjs, which will cause a TypeScript compilation error.
_{Severity: MEDIUM}

Suggested Fix

Remove MonitorConfig from the import statement from '@sentry/nestjs'. The correct type import from '@sentry/core' is already included in the code snippet.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent. Verify if this is a real issue. If it is, propose a fix; if not, explain why it's
not valid.

Location: packages/nestjs/README.md#L136

Potential issue: The code example in the `@sentry/nestjs` README includes
`MonitorConfig` in the import statement from `@sentry/nestjs`. However, `MonitorConfig`
is not a public export of the `@sentry/nestjs` package. TypeScript users who copy this
code snippet will encounter a compilation error because the type cannot be found in the
specified module. The correct import for this type is from `@sentry/core`, which is
already present in the example on the following line.

_{Did we get this right? 👍 / 👎 to inform future reviews.}