Clean up Module 08: Remove unconditional function calls

Fixed issue where performance analysis functions were called every time
the module was imported, instead of only when needed.

Changes:
- Commented out analyze_dataloader_performance() bare call
- Commented out analyze_memory_usage() bare call
- Removed redundant test_training_integration() comment

These functions are still defined and can be called manually for
performance insights, but won't run on every import.

The test_module() function still calls all necessary tests when
the module is run as __main__.

Result: Module imports cleanly without running expensive performance
benchmarks unless explicitly requested.

modules/source/08_dataloader/dataloader_dev.py

@@ -874,7 +874,7 @@ def analyze_dataloader_performance():
     print("• Memory usage scales linearly with batch size")
     print("🚀 Production tip: Balance batch size with GPU memory limits")
 
-# analyze_dataloader_performance()  # Moved to main block
+# analyze_dataloader_performance()  # Optional: Run manually for performance insights
 
 
 def analyze_memory_usage():
@@ -918,7 +918,7 @@ def analyze_memory_usage():
     print(f"  Large batch (512×784): {large_bytes / 1024:.1f} KB")
     print(f"  Ratio: {large_bytes / small_bytes:.1f}×")
 
-# analyze_memory_usage()  # Moved to main block
+# analyze_memory_usage()  # Optional: Run manually for memory insights
 
 
 # %% [markdown]
@@ -999,8 +999,6 @@ def test_training_integration():
 
     print("✅ Training integration works correctly!")
 
-# test_training_integration()  # Moved to main block
-
 
 # %% [markdown]
 """