Bump testsuite/rdf-tests from `5979a87` to `b9277b2`

Bumps [testsuite/rdf-tests](https://github.com/w3c/rdf-tests) from `5979a87` to `b9277b2`.
- [Release notes](https://github.com/w3c/rdf-tests/releases)
- [Commits](5979a87535...b9277b28c7)

Signed-off-by: dependabot[bot] <support@github.com>

testsuite/rdf-tests

@@ -1 +1 @@
-Subproject commit 5979a875356911ff0175a8f8a6c2d04edecdaac1
+Subproject commit b9277b28c7aa264bb146095b714873c22220ed57