fix(send): self-review fixes (FQCN, min_ansible_version str)

* tasks/main.yml: prefix all builtin modules with ansible.builtin
  (file, template) — silences ansible-lint fqcn[action-core] and
  matches the convention used by the other roles in this collection.

* meta/main.yml: change min_ansible_version from the float 2.14 to
  the string '2.14'. ansible-galaxy's schema requires a string here
  (ansible-lint schema[meta] complains otherwise — same fix I just
  applied to the opnform role).

roles/send/meta/main.yml

@@ -4,7 +4,7 @@ galaxy_info:
   description: Deploy a self-hosted Send (timvisee fork) instance with Redis via Docker Compose
   license: MIT
 
-  min_ansible_version: 2.14
+  min_ansible_version: "2.14"
 
   galaxy_tags:
     - send