Add CodeCov Token

[M. Fatih Cırıt]

Similar to:

• autowarefoundation/autoware.universe#7769

You should add the token following instructions from:

• https://github.com/codecov/codecov-action?tab=readme-ov-file#usage

And add it as a secret to your organization.

And apply it like these:

• autowarefoundation/autoware_cmake#9

Or CodeCov won't work for you.

cc. @mitsudome-r