[bug] Powerflow performance drop with newer versions

Bug report checklist

[X] Searched the issues page for similar reports
[X] Read the relevant sections of the documentation
[X] Browse the tutorials and tests for usefull code snippets and examples of use
[X] Reproduced the issue after updating with pip install --upgrade pandapower (or git pull)
[X] Tried basic troubleshooting (if a bug/error) like restarting the interpreter and checking the pythonpath

Reproducible Example

import timeit
import pandapower as pp

setup = """
import warnings
import pandapower as pp
import pandapower.networks as pn

warnings.filterwarnings("ignore")

net = pn.case9241pegase()
pp.runpp(net)  # first run for numba "compiling"
"""

number = 10

with_numba = timeit.timeit("pp.runpp(net, numba=True)", setup=setup, number=number)
without_numba = timeit.timeit("pp.runpp(net, numba=False)", setup=setup, number=number)

print(f"Pandapower version: {pp.__version__}")
print(f"With numba: {with_numba/number*1000:.1f} ms")
print(f"Without numba: {without_numba/number*1000:.1f} ms")

Issue Description and Traceback

Hello, I have noticed a performance drop with newer versions of pandapower when running the power flow. I have checked the performance with the snippet of code provided on 3 different pandapower versions, with the following results:

Pandapower version: 2.10.1 With numba: 272.48 ms Without numba: 360.51 ms

Pandapower version: 2.13.1 With numba: 1456.08 ms Without numba: 1528.37 ms

Pandapower version: 2.14.6 With numba: 3591.73 ms Without numba: 3685.65 ms

These 3 tests were done each time on a new python environment where only pandapower, numba and their dependencies were installed.

Could you please help me with this issue? Is the problem on my end?

Expected Behavior

The expected behavior is to have the same or close to the same performance with newer versions.

Installed Versions

python version: 3.10.14
pandas version: 2.2.2
networkx version: 3.3
scipy version: 1.13.0
numpy version: 1.26.4
tqdm version: 4.66.2
deepdiff version: 7.0.1
Operating System name/version: Ubuntu 22.04

Label

[x] Relevant labels are selected

e2nIEE / pandapower