Bump codecov/codecov-action from 3 to 4 #594

Job	Run time
C++ Tests on windows-latest	9m 8s
C++ Tests on windows-latest MinGW 13	5m 3s
C++ Tests on ubuntu-20.04 LLVM 8	2m 31s
Python 3.7 Tests on ubuntu-latest	1m 35s
C++ Tests on ubuntu-20.04 GCC 8	2m 41s
Tests on 32-bit Linux	4m 51s
C++ Tests on ubuntu-latest GCC 9	3m 43s
Python 3.11 Tests on ubuntu-latest	1m 33s
C++ Tests on ubuntu-latest GCC 13	3m 46s
Python pypy-3.9 Tests on ubuntu-latest	1m 41s
C++ Tests on macos-latest	4m 14s
Python 3.7 Tests on macos-latest	2m 7s
Python 3.11 Tests on macos-latest	1m 58s
Python pypy-3.9 Tests on macos-latest	1m 22s
Python 3.7 Tests on windows-latest	2m 35s
Python 3.11 Tests on windows-latest	2m 30s
Python pypy-3.9 Tests on windows-latest	2m 19s
	53m 37s

Provide feedback