Revert "Enable json validation for sdk"

This reverts commit 1b8ef645179ed48a032eb22b15983bb43660f202.

Reason for revert: Causing framework linux builder failure.

Original change's description:
> Enable json validation for sdk
> 
> Luci builder configs have now been available in separate repos. This CL enables validation of the config json file format for flutter recipes.
> 
> Change-Id: Ice879fe16cf47771c8ebb9450c1882154ebc9753
> Reviewed-on: https://flutter-review.googlesource.com/c/recipes/+/5340
> Commit-Queue: Keyong Han <keyonghan@google.com>
> Reviewed-by: Tong Wu <wutong@google.com>

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

Change-Id: I19b735399a04c9a9a83c742a51fc10de9b092f37
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://flutter-review.googlesource.com/c/recipes/+/5422
Reviewed-by: Keyong Han <keyonghan@google.com>
Commit-Queue: Keyong Han <keyonghan@google.com>
25 files changed
tree: 907deaee7dcc16d3ed5ba39d2af3cd1af71b373f
  1. infra/
  2. recipe_modules/
  3. recipes/
  4. .gitignore
  5. .style.yapf
  6. OWNERS
  7. recipes.py