[SYSTEMDS-3891] OOC k-Means Support

[janniklinde]

This patch adds support for the k-means builtin script in the out-of-core backend by introducing new instructions, handling parfor.

Additionally, this patch improves performance of the OOCLRUCacheScheduler under memory pressure by debouncing cleanup runs, which previously caused stalls due to long synchronization barriers.

Finally, this patch provides bugfixes for various instructions and stream lifecycle handling.

[codecov]

Codecov Report

❌ Patch coverage is 58.14932% with 398 lines in your changes missing coverage. Please review.
✅ Project coverage is 71.78%. Comparing base (743c902) to head (6e7439f).
⚠️ Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
...instructions/ooc/MatrixIndexingOOCInstruction.java	60.96%	63 Missing and 26 partials ⚠️
.../sysds/runtime/ooc/cache/OOCLRUCacheScheduler.java	64.32%	36 Missing and 25 partials ⚠️
...he/sysds/runtime/instructions/ooc/OOCWatchdog.java	0.00%	56 Missing ⚠️
...sysds/runtime/instructions/ooc/OOCInstruction.java	58.47%	33 Missing and 16 partials ⚠️
...rg/apache/sysds/runtime/ooc/stats/OOCEventLog.java	0.00%	37 Missing ⚠️
.../sysds/runtime/instructions/ooc/CachingStream.java	68.42%	20 Missing and 10 partials ⚠️
.../runtime/instructions/ooc/UnaryOOCInstruction.java	78.57%	7 Missing and 8 partials ⚠️
...runtime/instructions/ooc/BinaryOOCInstruction.java	0.00%	11 Missing and 3 partials ⚠️
...sds/runtime/controlprogram/ParForProgramBlock.java	72.97%	4 Missing and 6 partials ⚠️
...ds/runtime/instructions/ooc/TeeOOCInstruction.java	0.00%	6 Missing ⚠️
... and 15 more

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #2442      +/-   ##
============================================
+ Coverage     71.72%   71.78%   +0.06%     
- Complexity    48011    48219     +208     
============================================
  Files          1554     1554              
  Lines        184671   185352     +681     
  Branches      36248    36381     +133     
============================================
+ Hits         132453   133058     +605     
- Misses        41964    41998      +34     
- Partials      10254    10296      +42     

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