Provide instrumentations a way to exclude_urls that is not using environment variables

[cdvv7788]

https://github.com/open-telemetry/opentelemetry-python-contrib/blob/main/instrumentation/opentelemetry-instrumentation-fastapi/src/opentelemetry/instrumentation/fastapi/__init__.py#L40

Is your feature request related to a problem?
I want to get the urls to exclude from somewhere else than environment variables.

Describe the solution you'd like
Providing an argument to exclude_urls, using as default _exclude_urls (generated from environment variable) should be an option for other setups.

Describe alternatives you've considered
The fastapi instrumentation just adds a middleware. I copied that method with the additional variable as input.

Additional context
This is a simple addition, in case it is up to consideration. I can send a PR if that is ok.

[owais]

This is a simple addition, in case it is up to consideration. I can send a PR if that is ok.

@cdvv7788 Please feel free to send one or more :)

[ivergara]

Isn't this issue closed by #486?

[cdvv7788]

That is correct. Thanks!