Fix #943: replace one-line open() calls with context manager (#940)

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: mhucka

setup.py

@@ -124,13 +124,20 @@ def build_extension(self, ext):
         )
 
 
-requirements = open("requirements.txt").readlines()
-dev_requirements = open("dev-requirements.txt").readlines()
+with open("requirements.txt") as f:
+    requirements = [
+        line.strip() for line in f if line.strip() and not line.strip().startswith("#")
+    ]
+with open("dev-requirements.txt") as f:
+    dev_requirements = [
+        line.strip() for line in f if line.strip() and not line.strip().startswith("#")
+    ]
 
 description = "Schrödinger and Schrödinger-Feynman simulators for quantum circuits."
 
 # README file as long_description.
-long_description = open("README.md", encoding="utf-8").read()
+with open("README.md", encoding="utf-8") as f:
+    long_description = f.read()
 
 __version__ = runpy.run_path("qsimcirq/_version.py")["__version__"]
 if not __version__: