tests: Specify version for test PEP621 metadata (#867)

According to today's specification
https://packaging.python.org/en/latest/specifications/declaring-project-metadata/#specification

> The only keys required to be statically defined are:
  -  name
  The keys which are required but may be specified either
  statically or listed as dynamic are:
  - version

Fixes: #866

Signed-off-by: Stanislav Levin <slev@altlinux.org>

testing/test_integration.py

@@ -56,7 +56,8 @@ def test_pyproject_support(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> N
         "[tool.setuptools_scm]\ndist_name='setuptools_scm_example'"
     ),
     "pyproject.project": (
-        "[project]\nname='setuptools_scm_example'\n[tool.setuptools_scm]"
+        "[project]\nname='setuptools_scm_example'\n"
+        "dynamic=['version']\n[tool.setuptools_scm]"
     ),
 }