Address review feedback: add argparse import and missing dependsOn entries

- Add missing 'import argparse' (fixes NameError at runtime)
- Add libimagequant to PIL._imaging dependsOn (Thread 25)
- Add PIL._imagingtk dependsOn with libxcb (Threads 26 and 27)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: aclark4life

.github/generate-sbom.py

@@ -10,6 +10,7 @@
 
 from __future__ import annotations
 
+import argparse
 import datetime as dt
 import hashlib
 import json
@@ -446,6 +447,7 @@ def generate(version: str) -> dict:
                 "pkg:generic/zlib",
                 "pkg:generic/libtiff",
                 "pkg:generic/openjpeg",
+                "pkg:generic/libimagequant",
             ],
         },
         {
@@ -474,6 +476,10 @@ def generate(version: str) -> dict:
             "ref": f"{purl}#c-ext/PIL._imagingmath",
             "dependsOn": ["pkg:pypi/pybind11"],
         },
+        {
+            "ref": f"{purl}#c-ext/PIL._imagingtk",
+            "dependsOn": ["pkg:generic/libxcb"],
+        },
         {
             "ref": f"{purl}#thirdparty/raqm",
             "dependsOn": [