Revert "[engine] Add flutter deps"

This reverts commit 073d943e31a3108ec84bedeb111c60287142582d.

Reason for revert: The version in ci.yaml is wrong (it's missing "version:"

Original change's description:
> [engine] Add flutter deps
>
> Make flutter_deps error message more descriptive
>
> Reland of https://flutter-review.googlesource.com/c/recipes/+/16122
>
> Bug: https://github.com/flutter/flutter/issues/86892
> Change-Id: I3b3a707e8b995ee1749d800c3487c64ea1dd10e8
> Reviewed-on: https://flutter-review.googlesource.com/c/recipes/+/16301
> Commit-Queue: Casey Hillers <chillers@google.com>
> Reviewed-by: Godofredo Contreras <godofredoc@google.com>

TBR=godofredoc@google.com,chillers@google.com,flutter-scoped@luci-project-accounts.iam.gserviceaccount.com,egarciad@google.com

Change-Id: Id41bd92c3c2db1110f215ae7f5ab51479cffe58f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: https://github.com/flutter/flutter/issues/86892
Reviewed-on: https://flutter-review.googlesource.com/c/recipes/+/16366
Reviewed-by: Casey Hillers <chillers@google.com>
Commit-Queue: Casey Hillers <chillers@google.com>
diff --git a/recipe_modules/flutter_deps/api.py b/recipe_modules/flutter_deps/api.py
index f9275ce..1af8030 100644
--- a/recipe_modules/flutter_deps/api.py
+++ b/recipe_modules/flutter_deps/api.py
@@ -76,11 +76,7 @@
         continue
       dep_funct = available_deps.get(dep.get('dependency'))
       if not dep_funct:
-        msg = '''Dependency %s not available.
-
-        Ensure ci.yaml contains one of the following supported keys:
-        %s'''.format(dep.get('dependency'), available_deps.keys())
-        raise ValueError(msg)
+        raise ValueError('Dependency %s not available.' % dep)
       dep_funct(env, env_prefixes, dep.get('version'))
 
   def open_jdk(self, env, env_prefixes, version):
diff --git a/recipes/engine.py b/recipes/engine.py
index 0043090..169f63c 100644
--- a/recipes/engine.py
+++ b/recipes/engine.py
@@ -1572,11 +1572,6 @@
   # Delete derived data on mac. This is a noop for other platforms.
   api.os_utils.clean_derived_data()
 
-  # Ensure required deps are installed
-  api.flutter_deps.required_deps(
-      env, env_prefixes, api.properties.get('dependencies', [])
-  )
-
   # Various scripts we run assume access to depot_tools on path for `ninja`.
   with api.context(cwd=cache_root, env=env,
                    env_prefixes=env_prefixes), api.depot_tools.on_path():