The PDF text layer carries data tables (D3). Their sources and notices are
now in THIRD_PARTY.md (shipped in every archive through
THIRD_PARTY_NOTICES.md) and in the SBOM:
- the Adobe Glyph List subset (BSD-3-Clause, Copyright 2002-2019 Adobe),
- the printable-ASCII advance widths of Helvetica and Times-Roman from
Adobe's core-14 font metrics (the AFM files are not distributed),
- the Unicode Character Database data of pdf_unicode.c (Unicode
License v3, full text included).
scripts/gen-pdf-unicode.py (stdlib CPython only) regenerates
pdf_unicode.c byte for byte with CPython 3.14.6 (Unicode 16.0.0);
pdf_tables.c is maintained data from here on. License texts were taken
from their sources (adobe-type-tools/agl-aglfn, unicode.org).
Signed-off-by: Martin Vogel <martin.vogel.tech@gmail.com>