Bump waste_carriers_engine from d0cca34 to a7700e0 (#1320)

Bumps [waste_carriers_engine](https://github.com/DEFRA/waste-carriers-engine) from `d0cca34` to `a7700e0`.
- [Commits](DEFRA/waste-carriers-engine@d0cca34...a7700e0)

---
updated-dependencies:
- dependency-name: waste_carriers_engine
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: PaulDoyle-DEFRA <[email protected]>

Gemfile.lock

@@ -10,7 +10,7 @@ GIT
 
 GIT
   remote: https://github.com/DEFRA/waste-carriers-engine
-  revision: d0cca342b718f073662b186bd0bfaabf58760f39
+  revision: a7700e02edb3cb841256cfb4dad7a5ff238e9fe1
   branch: main
   specs:
     waste_carriers_engine (0.0.1)
@@ -479,8 +479,7 @@ GEM
       simplecov_json_formatter (~> 0.1)
     simplecov-html (0.12.3)
     simplecov_json_formatter (0.1.4)
-    simpleidn (0.2.2)
-      unf (~> 0.1.4)
+    simpleidn (0.2.3)
     spring (4.2.1)
     sprockets (4.2.1)
       concurrent-ruby (~> 1.0)
@@ -505,9 +504,6 @@ GEM
       execjs (>= 0.3.0, < 3)
     uk_postcode (2.1.8)
     unaccent (0.4.0)
-    unf (0.1.4)
-      unf_ext
-    unf_ext (0.0.9.1)
     unicode-display_width (2.5.0)
     validates_email_format_of (1.8.2)
       i18n (>= 0.8.0)