feat(tvl-kit): Expose //tools/checks in tvl-kit

This makes CI utility functions available in TVL kit. For now this is
only the Terraform check, but said check has come up in other repos
before so it's useful to centralise here (and we might add more!)

Change-Id: I18acb19fc3407650ab9bad53dfba022dda498c07
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5858
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: asmundo <asmundo@gmail.com>

views/kit/default.nix

@@ -25,6 +25,7 @@ pkgs.lib.fix (self: {
     depot.nix.readTree = self.readTree;
   };
 
+  checks = import ./checks { inherit pkgs; };
   lazy-deps = import ./lazy-deps { inherit pkgs; };
   magrathea = import ./magrathea { inherit pkgs; };
   readTree = import ./readTree { };