fix(functions): resolve deno lint errors in generated edge function template

the template generated by 'supabase functions new' produces deno lint errors
on line 6 due to inline jsr: import without version specifier:

  import jsr:@supabase/functions-js/edge-runtime.d.ts

this triggers two default deno lint rules:
  - no-import-prefix: inline jsr: dependency not allowed
  - no-unversioned-import: missing version in specifier

fix moves the dependency declaration to deno.json with proper versioning
and updates index.ts to use bare specifier import as recommended by deno.

closes #4424

Author: 7ttp

internal/functions/new/templates/deno.json

@@ -1,3 +1,5 @@
 {
-  "imports": {}
+  "imports": {
+    "@supabase/functions-js": "jsr:@supabase/functions-js@^2"
+  }
 }

internal/functions/new/templates/index.ts

@@ -3,7 +3,7 @@
 // This enables autocomplete, go to definition, etc.
 
 // Setup type definitions for built-in Supabase Runtime APIs
-import "jsr:@supabase/functions-js/edge-runtime.d.ts"
+import "@supabase/functions-js/edge-runtime.d.ts"
 
 console.log("Hello from Functions!")