threading.currentThread has been deprecated in favour of threading.current_thread in Python 3.10

[tirkarthi]

Describe the bug

threading.currentThread has been deprecated in favour of threading.current_thread in Python 3.10 . current_thread is also available in Python 2.7

To Reproduce
How can we reproduce the problem? Please be specific. Don't just link to a failing CI job. Answer the questions below:

1. What version of Python are you using? CPython master branch
2. What version of coverage.py are you using? The output of coverage debug sys is helpful.
3. What versions of what packages do you have installed? The output of pip freeze is helpful.
4. What code are you running? Give us a specific commit of a specific repo that we can check out.
5. What commands did you run?

rg -t py -w 'currentThread|notifyAll|activeCount|getName|setName|isDaemon|setDaemon' 
tests/test_concurrency.py
521:        ident = threading.currentThread().ident

coverage/pytracer.py
88:                    self.threading.currentThread().ident,
223:                self.thread = self.threading.currentThread()
225:                if self.thread.ident != self.threading.currentThread().ident:
246:        if self.threading and self.thread.ident != self.threading.currentThread().ident:

Expected behavior

currentThread needs to be replaced with current_thread which is also available in Python 2.7

Additional context

CPython PR : python/cpython#25174