Slightly better typings for ModelProviders

Still not great because the `any`s loosen some call sites up more than I'd like, but better than the broken types before.

src/server/utils/parseConstructFn.ts

@@ -70,7 +70,6 @@ export default async function parseConstructFn(
     // We've validated the JSON schema so this should be safe
     const input = prompt.input as Parameters<(typeof provider)["getModel"]>[0];
 
-    // @ts-expect-error TODO FIX ASAP
     const model = provider.getModel(input);
     if (!model) {
       return {
@@ -80,8 +79,6 @@ export default async function parseConstructFn(
 
     return {
       modelProvider: prompt.modelProvider as keyof typeof modelProviders,
-      // @ts-expect-error TODO FIX ASAP
-
       model,
       modelInput: input,
     };