feat: no strict dep5 parsing

Since version 0.1.47 of python-debian the dep5 parsing is strict. This is
causing issues for certain users that have multiple Copyright statements in
their Dep5 file. Disablng strictness removes the issue for those users.

Closes #803

Signed-off-by: Nico Rikken <nico.rikken@fsfe.org>

src/reuse/project.py

@@ -306,7 +306,7 @@ def _copyright(self) -> Optional[Copyright]:
             copyright_path = self.root / ".reuse/dep5"
             try:
                 with copyright_path.open(encoding="utf-8") as fp:
-                    self._copyright_val = Copyright(fp)
+                    self._copyright_val = Copyright(fp, strict=False)
             except OSError:
                 _LOGGER.debug("no .reuse/dep5 file, or could not read it")
             except DebianError:

tests/conftest.py

@@ -298,7 +298,7 @@ def dep5_copyright():
     with (RESOURCES_DIRECTORY / "fake_repository/.reuse/dep5").open(
         encoding="utf-8"
     ) as fp:
-        return Copyright(fp)
+        return Copyright(fp, strict=False)
 
 
 @pytest.fixture()