fix: Create file for streaming sink even if unspawned

[coastalwhite]

Fixes #23084.

[codecov]

Codecov Report

Attention: Patch coverage is 87.20000% with 48 lines in your changes missing coverage. Please review.

Project coverage is 81.28%. Comparing base (3588b2b) to head (805700e).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...lars-stream/src/nodes/io_sinks/partition/parted.rs	0.00%	38 Missing ⚠️
crates/polars-stream/src/nodes/io_sinks/mod.rs	65.51%	10 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #23672      +/-   ##
==========================================
- Coverage   81.30%   81.28%   -0.02%     
==========================================
  Files        1642     1642              
  Lines      223176   223362     +186     
  Branches     2837     2837              
==========================================
+ Hits       181447   181569     +122     
- Misses      41030    41094      +64     
  Partials      699      699              

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[ritchie46]

Nice, is this good to go. I think it can fix distributed.

[coastalwhite]

@orlp wanted to do it a bit differently. If he did his small refactor, I can rebase this PR.