release: 3.40.2 — file-filter reset (✕) button

A red ✕ next to the filter selector appears whenever the filter is not
"All" and resets it to "All" in one click (pysimFsFilterClear).  Bump
VERSION/pyproject/PWA header to 3.40.2 and the SW cache to simple-v487.

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "pysim-simple-server"
-version = "3.40.1"
+version = "3.40.2"
 description = "HTTP REST server wrapping pysim for the SIMple PWA"
 license = { text = "GPL-2.0-or-later" }
 requires-python = ">=3.9"