`DataFrame.head()` only returns rows from first partition of `dask.datasets.timeseries`

[charlesbluca]

Describe the issue: Seems like head() only returns results from the first partition of dask.datasets.timeseries, even if npartitions is overridden.

Minimal Complete Verifiable Example:

from dask.datasets import timeseries

ddf = timeseries(freq="1d")
print(len(ddf)) 
# 30

print(ddf.head(30, npartitions=-1))
#              name    id         x         y
# timestamp                                  
# 2000-01-01  Edith  1061 -0.843924 -0.443468

Environment:

• Dask version: 2024.4.1
• Dask-expr version: 1.0.10
• Python version: 3.10
• Operating System: ubuntu20.04
• Install method (conda, pip, source): conda