bug: `Error: spawn ... snyk ENOENT`

[asos-craigmorten]

Issue

Details

When using npx @asos/snyker and snyk or @asos/snyker hasn't been globally installed you get the following error:

$ npx @asos/snyker
Need to install the following packages:
  @asos/snyker
Ok to proceed? (y) y
[SNYKER: STARTING]
[SNYKER: STEP 1]: Ensuring lockfile 'yarn.lock' is up to date.

yarn install v1.22.15
info No lockfile found.
[1/4] Resolving packages...
[2/4] Fetching packages...
[3/4] Linking dependencies...
[4/4] Building fresh packages...

success Saved lockfile.
Done in 0.21s.

[SNYKER: STEP 2]: Deleting '.snyk' file.
[SNYKER: STEP 3]: Getting vulnerable paths from Snyk.
An error was thrown while executing the previous command.
{
  error: Error: spawn /root/.npm/_npx/41eaf48ba153073a/node_modules/@asos/snyker/node_modules/.bin/snyk ENOENT
      at Process.ChildProcess._handle.onexit (node:internal/child_process:282:19)
      at onErrorNT (node:internal/child_process:477:16)
      at processTicksAndRejections (node:internal/process/task_queues:83:21) {
    errno: -2,
    code: 'ENOENT',
    syscall: 'spawn /root/.npm/_npx/41eaf48ba153073a/node_modules/@asos/snyker/node_modules/.bin/snyk',
    path: '/root/.npm/_npx/41eaf48ba153073a/node_modules/@asos/snyker/node_modules/.bin/snyk',
    spawnargs: [
      'test',
      '--dev',
      '--json',
      '--ignore-policy',
      '--strict-out-of-sync=true',
      '--file=yarn.lock',
      '--prune-repeated-dependencies'
    ]
  }
}
Retrying...
An error was thrown while executing the previous command.
{
  error: Error: spawn /root/.npm/_npx/41eaf48ba153073a/node_modules/@asos/snyker/node_modules/.bin/snyk ENOENT
      at Process.ChildProcess._handle.onexit (node:internal/child_process:282:19)
      at onErrorNT (node:internal/child_process:477:16)
      at processTicksAndRejections (node:internal/process/task_queues:83:21) {
    errno: -2,
    code: 'ENOENT',
    syscall: 'spawn /root/.npm/_npx/41eaf48ba153073a/node_modules/@asos/snyker/node_modules/.bin/snyk',
    path: '/root/.npm/_npx/41eaf48ba153073a/node_modules/@asos/snyker/node_modules/.bin/snyk',
    spawnargs: [
      'test',
      '--dev',
      '--json',
      '--ignore-policy',
      '--strict-out-of-sync=true',
      '--file=yarn.lock',
      '--prune-repeated-dependencies'
    ]
  }
}
Exiting...

This is as a result of the hardcorded path to the snyk binary, which is incorrect in npx contexts.