Revert "[SDK] Adds an SDK hash to kernels and the VM."

This reverts commit edde575dcd.

Reason for revert: Breaks the Dart to Flutter roll and golem

Original change's description:
> [SDK] Adds an SDK hash to kernels and the VM.
>
> Adds a new SDK hash to kernels and the VM which is optionally checked
> to verify kernels are built for the same SDK as the VM.
> This helps catch incompatibilities that are currently causing
> subtle bugs and (not so subtle) crashes.
>
> The SDK hash is encoded in kernels as a new field in components.
> The hash is derived from the 10 byte git short hash.
>
> This new check can be disabled via:
>   tools/gn.py ... --no-verify-sdk-hash
>
> This CL bumps the min. (and max.) supported kernel format version,
> making the VM backwards incompatible from this point back.
>
> Bug: https://github.com/dart-lang/sdk/issues/41802
> Change-Id: I3cbb2d481239ee64dafdaa0e4aac36c80281931b
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/150343
> Commit-Queue: Clement Skau <cskau@google.com>
> Reviewed-by: Jens Johansen <jensj@google.com>
> Reviewed-by: Martin Kustermann <kustermann@google.com>

TBR=kustermann@google.com,jensj@google.com,cskau@google.com

Change-Id: I34cc7d378e2babdaaca4d932d19c19d0f35422fc
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: https://github.com/dart-lang/sdk/issues/41802
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/152703
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Siva Annamalai <asiva@google.com>

sdk_args.gni

@@ -19,22 +19,4 @@ declare_args() {
   # to out/ReleaseX64/args.gn. The path above can be extracted from the `.git`
   # file under the git worktree folder.
   default_git_folder = "$_dart_root/.git"
-
-  # Whether to enable the SDK hash check that will prevent loading a kernel
-  # into a VM which was built with a different SDK.
-  verify_sdk_hash = true
-}
-
-# The SDK hash to build into VM and kernels.
-# The value 0000000000 signifies no hash is set, which will disable the check.
-if (verify_sdk_hash) {
-  sdk_hash = exec_script("$_dart_root/tools/make_version.py",
-                         [ "--format={{GIT_HASH}}" ],
-                         "trim string",
-                         [
-                           "$_dart_root/tools/VERSION",
-                           "$_dart_root/tools/utils.py",
-                         ])
-} else {
-  sdk_hash = "0000000000"
 }