Fix CI platform-specific type checker installation

The test-cygwin fast and perf jobs failed while installing the project test extra. basedpyright pulled nodejs-wheel-binaries, whose Cygwin source build recursively required cmake and ninja and then failed because no make program was available.

Exclude Cygwin from the basedpyright requirement because the type check runs only in the Ubuntu Python 3.12 job. Also add the final newline that the lint end-of-file-fixer check required for the generated baseline.

Author: codex

.basedpyright/baseline.json

@@ -1125,4 +1125,4 @@
             }
         ]
     }
-}
+}

test-requirements.txt

@@ -1,5 +1,5 @@
 coverage[toml]
-basedpyright==1.39.9 ; python_version >= "3.9"
+basedpyright==1.39.9 ; python_version >= "3.9" and sys_platform != "cygwin"
 ddt >= 1.1.1, != 1.4.3
 mock ; python_version < "3.8"
 mypy==1.18.2 ; python_version >= "3.9" # pin mypy version to avoid new errors