What happened?

In L136 if the deprecated capabilities option is None the default is set to DesiredCapabilities.FIREFOX
Then in L168
The deprecated default from acceptInsecureCerts overwrites the set value from the options object.

I am happy to put the proposed changes in a PR with the changes proposed below (Do not initialize deprecated parameters to a default use empty dict instead):

https://github.com/SeleniumHQ/selenium/blob/trunk/py/selenium/webdriver/firefox/webdriver.py#L135-L140

        if capabilities is None:
            capabilities = {}
        if not options:
            options = Options()

How can we reproduce the issue?

from selenium import webdriver
from selenium.webdriver.firefox.options import Options

options = Options()
options.accept_insecure_certs = False

driver = webdriver.Firefox(options=options)
driver.capabilities()

yields:

{'acceptInsecureCerts': True,
 'browserName': 'firefox',
...

### Relevant log output

```shell
.

Operating System

Linux

Selenium version

python selenium==4.1.2

What are the browser(s) and version(s) where you see this issue?

Firefox 98.0

What are the browser driver(s) and version(s) where you see this issue?

gecko 0.30.0

Are you using Selenium Grid?

No response