Fix dependency syntax error in test_dist_info

Fix the install_requires used in test_dist_info to use the dangling
syntax, in order to correctly handle markers.  This fixes syntax error
when parsed by packaging-22.0+, as well as setuptools warning:

```
UserWarning: One of the parsed requirements in `install_requires` looks like a valid environment marker: \'sys_platform != "linux"\'
Make sure that the config is correct and check https://setuptools.pypa.io/en/latest/userguide/declarative_config.html#opt-2
  warnings.warn(msg, UserWarning)\n'
```

Author: mgorny

setuptools/tests/test_dist_info.py

@@ -142,7 +142,8 @@ class TestWheelCompatibility:
     version = {version}
 
     [options]
-    install_requires = foo>=12; sys_platform != "linux"
+    install_requires =
+        foo>=12; sys_platform != "linux"
 
     [options.extras_require]
     test = pytest