Fix any type usage in the saas/ folder (#5934)

# Description of Changes
Ages ago I made #4835 to try and fix all the `any` type usage in the
system but never got it finished, and there were just too many to review
and ensure it still worked. There's even more now.

My new tactic is to fix folder by folder. This fixes the `any` typing in
the `saas/` folder, and also enables `no-unnecessary-type-assertion`,
which really helps reduce pointless `as` casts that AI generates when
the type is already known. I hope to expand both of these to the rest of
the folders soon, but one folder is better than none.

frontend/src/saas/components/shared/config/configSections/PasswordSecurity.tsx

@@ -55,8 +55,8 @@ const PasswordSecurity: React.FC = () => {
         setOpened(false);
         setDidUpdate(false);
       }, 2000);
-    } catch (e: any) {
-      setError(e?.message || 'Failed to change password');
+    } catch (e: unknown) {
+      setError(e instanceof Error ? e.message : 'Failed to change password');
     } finally {
       setIsLoading(false);
     }