New Features (ENH):
-  Add writer.pdf_header property (getter and setter) (#1038)

Performance Improvements (PI):
-  Remove b_ call in FloatObject.write_to_stream (#1044)
-  Check duplicate objects in writer._sweep_indirect_references (#207)

Documentation (DOC):
-  How to surppress exceptions/warnings/log messages (#1037)
-  Remove hyphen from lossless (#1041)
-  Compression of content streams (#1040)
-  Fix inconsistent variable names in add-watermark.md (#1039)
-  File size reduction
-  Add CHANGELOG to the rendered docs (#1023)

Maintenance (MAINT):
-  Handle XML error when reading XmpInformation (#1030)
-  Deduplicate Code / add mutmut config (#1022)

Code Style (STY):
-  Use unnecessary one-line function / class attribute (#1043)
-  Docstring formatting (#1033)

Full Changelog: 2.4.0...2.4.1