fix: doc convert docx failed

.gitmodules

@@ -1,6 +0,0 @@
-[submodule "src/bisheng-unstructured"]
-	path = src/bisheng-unstructured
-	url = https://github.com/dataelement/bisheng-unstructured.git
-[submodule "src/bisheng-rt"]
-	path = src/bisheng-rt
-	url = https://github.com/dataelement/bisheng-rt.git

src/backend/bisheng/api/services/libreoffice_converter.py

@@ -89,7 +89,7 @@ def convert_doc_to_docx(input_doc_path, output_dir=None):
         soffice_path,
         "--headless",  # Run in headless mode (no GUI)
         "--convert-to",
-        "docx",  # Specify the output format
+        "docx:Office Open XML Text",  # Specify the output format
         "--outdir",
         output_dir,  # Specify the output directory
         input_doc_path,  # The input file