Remove C extension that has no deps

Author: hugovk

.github/generate-sbom.py

@@ -487,10 +487,6 @@ def generate(version: str) -> dict:
             "ref": f"{purl}#c-ext/PIL._avif",
             "dependsOn": ["pkg:generic/libavif"],
         },
-        {
-            "ref": f"{purl}#c-ext/PIL._imagingtk",
-            "dependsOn": [],
-        },
         {
             "ref": f"{purl}#thirdparty/raqm",
             "dependsOn": [