Chore: Move the four duplicated parser sample PDFs into a shared paperless_testing location

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

pyproject.toml

@@ -256,8 +256,8 @@ isort.force-single-line = true
 [tool.codespell]
 ignore-words-list = "criterias,afterall,valeu,ureue,equest,ure,assertIn,Oktober,commitish,NIN,nin,reprot"
 skip = """\
-  src-ui/src/locale/*,src-ui/pnpm-lock.yaml,src-ui/e2e/*,src/paperless_mail/tests/samples/*,src/paperless/tests/samples\
-  /mail/*,src/documents/tests/samples/*,*.po,*.json\
+  src-ui/src/locale/*,src-ui/pnpm-lock.yaml,src-ui/e2e/*,src/paperless/tests/samples/mail/*,src/documents/tests/samples\
+  /*,src/paperless_testing/sample_files/*,*.po,*.json\
   """
 write-changes = true