fix(deps): bump electron to 43.8.3 and undici to 7.30.1

- Pick up upstream security fixes
- Update undici override to match
- Add security changelog fragment

changes/security-deps-electron-undici.md

@@ -0,0 +1,4 @@
+type: fixed
+area: security
+
+- Electron is updated to 43.8.3 and undici to 7.30.1 to pick up security fixes.