[FEAT] Add ceil function

[NormallyGaussian]

Adding the ceil function to match https://ibis-project.org/reference/expression-numeric#ibis.expr.types.numeric.NumericValue.ceil. Added tests with example usage.

This is my first PR here. Happy to take on more of the functions in #1037 after getting through this one.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (9b6cb94) 85.52% compared to head (1d1076e) 85.54%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1867      +/-   ##
==========================================
+ Coverage   85.52%   85.54%   +0.01%     
==========================================
  Files          55       55              
  Lines        6185     6190       +5     
==========================================
+ Hits         5290     5295       +5     
  Misses        895      895              

Files	Coverage Δ
daft/expressions/expressions.py	90.93% <100.00%> (+0.06%)	⬆️
daft/series.py	92.87% <100.00%> (+0.03%)	⬆️

[samster25]

Congrats on your first contribution! And wow, this looks perfect! I don't have any feedback to give! This should go out in tomorrow's release.

Also we would love if you could contribute more from the ibis list!