chore(lint): enable flake8-type-checking ruff rules

- TCH003 Move standard library import `io` into a type-checking block

https://beta.ruff.rs/docs/rules/#flake8-type-checking-tch

Author: László Vaskó

pyproject.toml

@@ -85,6 +85,7 @@ select = [
   "SLF",    # flake8-self
   "T10",    # flake8-debugger
   "T20",    # flake8-print
+  "TCH",    # flake8-type-checking
   "TRY",    # tryceratops
   "UP",     # pyupgrade
   "W",      # pycodestyle (warnings)

unblob/extractors/command.py

@@ -1,14 +1,16 @@
-import io
 import shlex
 import subprocess
 from pathlib import Path
-from typing import List, Optional, Union
+from typing import TYPE_CHECKING, List, Optional, Union
 
 from structlog import get_logger
 
 from unblob.models import ExtractError, Extractor
 from unblob.report import ExtractCommandFailedReport, ExtractorDependencyNotFoundReport
 
+if TYPE_CHECKING:
+    import io
+
 logger = get_logger()
 
 
@@ -27,7 +29,7 @@ def extract(self, inpath: Path, outdir: Path):
         cmd = self._make_extract_command(inpath, outdir)
         command = shlex.join(cmd)
         logger.debug("Running extract command", command=command)
-        stdout_file: Union[int, io.FileIO] = subprocess.PIPE
+        stdout_file: Union[int, "io.FileIO"] = subprocess.PIPE
 
         def no_op():
             pass