Fix some remaining TODO comments

src/pip/_internal/pyproject.py

@@ -131,13 +131,12 @@ def load_pyproject_toml(use_pep517, pyproject_toml, setup_py, req_name):
         # (which is neede by the backend) in their requirements. So we
         # make a note to check that those requirements are present once
         # we have set up the environment.
-        # TODO: Review this - it's quite a lot of work to check for a very
-        # specific case. The problem is, that case is potentially quite
-        # common - projects that adopted PEP 518 early for the ability to
-        # specify requirements to execute setup.py, but never considered
-        # needing to mention the build tools themselves. The original PEP
-        # 518 code had a similar check (but implemented in a different
-        # way).
+        # This is quite a lot of work to check for a very specific case. But
+        # the problem is, that case is potentially quite common - projects that
+        # adopted PEP 518 early for the ability to specify requirements to
+        # execute setup.py, but never considered needing to mention the build
+        # tools themselves. The original PEP 518 code had a similar check (but
+        # implemented in a different way).
         backend = "setuptools.build_meta"
         check = ["setuptools>=40.2.0", "wheel"]
 

src/pip/_internal/req/req_install.py

@@ -117,7 +117,6 @@ def __init__(self, req, comes_from, source_dir=None, editable=False,
         self.pyproject_requires = None
 
         # Build requirements that we will check are available
-        # TODO: We don't do this for --no-build-isolation. Should we?
         self.requirements_to_check = []
 
         # The PEP 517 backend we should use to build the project