fix(ec2): timeout ssh tryKeyGen to avoid hanging #5951

## Problem
Starting in #5936 some
tests started expiring, since fixed in
#5954. However, than
expire, the `SshKeyPair` tests hang because they are stuck in a child
process. This leads to these tests failing to timeout, even when
exceeding the test timeout threshold.

## Solution
Add explicit timeout on the child process we use to spawn ssh keys.

Author: Hweinstock

packages/core/src/awsService/ec2/sshKeyPair.ts

@@ -80,6 +80,7 @@ export class SshKeyPair {
         }
         return !(await tryRun('ssh-keygen', ['-t', keyType, '-N', '', '-q', '-f', keyPath], 'yes', 'unknown key type', {
             onStdout: overrideKeys,
+            timeout: new Timeout(5000),
         }))
     }