kunit: tool: drop last uses of collections.namedtuple

Since we formally require python3.7+ since commit df4b0807ca1a
("kunit: tool: Assert the version requirement"), we can just use
@dataclasses.dataclass instead.

In kunit_config.py, we used namedtuple to create a hashable type that
had `name` and `value` fields and had to subclass it to define a custom
`__str__()`.
@datalcass lets us just define one type instead.

In qemu_config.py, we use namedtuple to allow modules to define various
parameters. Using @dataclass, we can add type-annotations for all these
fields, making our code more typesafe and making it easier for users to
figure out how to define new configs.

Signed-off-by: Daniel Latypov <[e-mail]>
Reviewed-by: David Gow <[e-mail]>
Reviewed-by: Brendan Higgins <[e-mail]>
Signed-off-by: Shuah Khan <[e-mail]>

tools/testing/kunit/kunit_config.py

···
 # Author: Felix Guo <[e-mail]>
 # Author: Brendan Higgins <[e-mail]>
 
-import collections
+from dataclasses import dataclass
 import re
 from typing import List, Set
 
 CONFIG_IS_NOT_SET_PATTERN = r'^# CONFIG_(\w+) is not set$'
 CONFIG_PATTERN = r'^CONFIG_(\w+)=(\S+|".*")$'
 
-KconfigEntryBase = collections.namedtuple('KconfigEntryBase', ['name', 'value'])
-
-class KconfigEntry(KconfigEntryBase):
+@dataclass(frozen=True)
+class KconfigEntry:
+	name: str
+	value: str
 
 	def __str__(self) -> str:
 		if self.value == 'n':

tools/testing/kunit/qemu_config.py

···
 # Copyright (C) 2021, Google LLC.
 # Author: Brendan Higgins <[e-mail]>
 
-from collections import namedtuple
+from dataclasses import dataclass
+from typing import List
 
 
-QemuArchParams = namedtuple('QemuArchParams', ['linux_arch',
-					       'kconfig',
-					       'qemu_arch',
-					       'kernel_path',
-					       'kernel_command_line',
-					       'extra_qemu_params'])
+@dataclass(frozen=True)
+class QemuArchParams:
+  linux_arch: str
+  kconfig: str
+  qemu_arch: str
+  kernel_path: str
+  kernel_command_line: str
+  extra_qemu_params: List[str]