use threading.Lock for cache maintenance functions

[AhmetNSimsek]

Solves #489

[codecov-commenter]

Codecov Report

Merging #496 (269dc2d) into main (5a0e6b3) will increase coverage by 1.45%.
Report is 186 commits behind head on main.
The diff coverage is 35.86%.

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@@            Coverage Diff             @@
##             main     #496      +/-   ##
==========================================
+ Coverage   36.81%   38.27%   +1.45%     
==========================================
  Files          61       62       +1     
  Lines        5421     5816     +395     
==========================================
+ Hits         1996     2226     +230     
- Misses       3425     3590     +165     

Files	Coverage Δ
siibra/core/atlas.py	85.71% <ø> (+1.23%)	⬆️
siibra/features/connectivity/__init__.py	83.33% <100.00%> (ø)
...ibra/features/connectivity/tracing_connectivity.py	75.00% <100.00%> (ø)
siibra/features/image/__init__.py	100.00% <100.00%> (ø)
siibra/features/tabular/layerwise_cell_density.py	37.20% <ø> (+0.25%)	⬆️
siibra/locations/boundingbox.py	19.88% <ø> (ø)
siibra/configuration/configuration.py	42.35% <0.00%> (ø)
...a/features/connectivity/functional_connectivity.py	55.55% <0.00%> (ø)
siibra/livequeries/ebrains.py	25.35% <0.00%> (+0.35%)	⬆️
siibra/volumes/__init__.py	83.33% <50.00%> (-16.67%)	⬇️
... and 31 more

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[AhmetNSimsek]

TO-DO:
Use the following design scheme instead:

from functools import wraps

def get_lock(filepath: str):
    def outer(fn):
        @wraps(fn)
        def inner(*args, **kwargs):
            with FileLock(filepath):
                return fn(*args, **kwargs)
        return inner
    return outer


@get_lock("access_cache")
def warm_cache():
    pass

@get_lock("access_cache")
def maintenance():
    ...

[AhmetNSimsek]

This is not working as intended. Using #496 (comment) is still an option but a more comprehensive maintenance of cache.py is required. Closing this PR for an an alternative including a comprehensive maintenance and filelock.