Revert back to github occt uri due to persistent 500

nix/build-all.py

@@ -614,7 +614,7 @@ if USE_OCCT and "occ" in targets:
             "-DBUILD_RELEASE_DISABLE_EXCEPTIONS=Off",
             f"-D3RDPARTY_FREETYPE_DIR={DEPS_DIR}/install/freetype"
         ],
-        download_url = "https://git.dev.opencascade.org/repos/occt.git",
+        download_url = "https://github.com/Open-Cascade-SAS/OCCT",
         download_name = "occt",
         download_tool=download_tool_git,
         patch=patches,

win/build-deps.cmd

@@ -395,7 +395,7 @@ if not %ERRORLEVEL%==0 goto :Error
 set DEPENDENCY_NAME=Open CASCADE %OCCT_VERSION%
 set DEPENDENCY_DIR=%DEPS_DIR%\occt_git
 cd "%DEPS_DIR%"
-call :GitCloneAndCheckoutRevision https://git.dev.opencascade.org/repos/occt.git "%DEPENDENCY_DIR%" %OCCT_VER%
+call :GitCloneAndCheckoutRevision https://github.com/Open-Cascade-SAS/OCCT "%DEPENDENCY_DIR%" %OCCT_VER%
 if not %ERRORLEVEL%==0 goto :Error
 
 :: Patching always blindly would trigger a rebuild each time