chore: update PDF paths in REUSE.toml

Update paths to reflect new organization in pdfs/ subdirectory:
- tests/php/fixtures/real_jsignpdf_level1.pdf -> tests/php/fixtures/pdfs/real_jsignpdf_level1.pdf
- tests/php/fixtures/small_valid-signed.pdf -> tests/php/fixtures/pdfs/small_valid-signed.pdf
- tests/php/fixtures/small_valid.pdf -> tests/php/fixtures/pdfs/small_valid.pdf

Signed-off-by: Vitor Mattos <1079143+vitormattos@users.noreply.github.com>

Author: vitormattos

REUSE.toml

@@ -50,9 +50,9 @@ path = [
     "src/types/openapi/openapi.ts",
     "tests/php/Unit/Handler/mock/cert.json",
     "tests/php/fixtures/cfssl/newcert-with-success.json",
-    "tests/php/fixtures/real_jsignpdf_level1.pdf",
-    "tests/php/fixtures/small_valid-signed.pdf",
-    "tests/php/fixtures/small_valid.pdf",
+    "tests/php/fixtures/pdfs/real_jsignpdf_level1.pdf",
+    "tests/php/fixtures/pdfs/small_valid-signed.pdf",
+    "tests/php/fixtures/pdfs/small_valid.pdf",
     "tests/integration/composer.json",
     "tests/integration/composer.lock",
     "tests/integration/features/**/*.feature",