pytest: fix remaining code checker warnings

- curl.py: delete commented no-op code.
- certs.py, curl.py: narrow down exceptions to fix:
  Except block handles 'BaseException'
- test_20_websockets: add comment to empty except branch.

Reported by GitHub CodeQL

Closes #21924

tests/http/test_20_websockets.py

@@ -264,6 +264,8 @@ class TestWebsockets:
                         f = b"\x88\x00"  # CLOSE frame
                         c.sendall(f)
                     except OSError:
+                        # Client may close/reset while we intentionally flood frames.
+                        # Send errors are expected here, ignore them.
                         pass
                     time.sleep(1)
                     c.close()

tests/http/testenv/certs.py

@@ -484,8 +484,7 @@ class TestCA:
             else:
                 try:
                     names.append(x509.IPAddress(ipaddress.ip_address(name)))
-                # TODO: specify specific exceptions here
-                except:  # noqa: E722
+                except ValueError:
                     names.append(x509.DNSName(name))
 
         return csr.add_extension(

tests/http/testenv/curl.py

@@ -284,11 +284,10 @@ class ExecResult:
         if with_stats:
             self._parse_stats()
         else:
-            # noinspection PyBroadException
             try:
                 out = ''.join(self._stdout)
                 self._json_out = json.loads(out)
-            except:  # noqa: E722
+            except (json.JSONDecodeError, TypeError, ValueError):
                 pass
 
     def __repr__(self):
@@ -300,8 +299,7 @@ class ExecResult:
         for line in self._stdout:
             try:
                 self._stats.append(json.loads(line))
-            # TODO: specify specific exceptions here
-            except:  # noqa: E722
+            except (json.JSONDecodeError, TypeError, ValueError):
                 log.exception(f'not a JSON stat: {line}')
                 break
 
@@ -1031,8 +1029,6 @@ class CurlClient:
                                          cwd=self._run_dir, shell=False,
                                          env=self._run_env)
                     profile = RunProfile(p.pid, started_at, self._run_dir)
-                    #if intext is not None and False:
-                    #    p.communicate(input=intext.encode(), timeout=1)
                     if self._with_perf:
                         perf = PerfProfile(p.pid, self._run_dir)
                         perf.start()