executors: bump firecracker kernel to 5.10.135

Created by: Strum355

Changes the kernel docker image used by ignite from the default weaveworks/ignite-kernel to sourcegraph/ignite-kernel:5.10.135-amd64. This addresses the Dirtypipe vulnerability fixed in 5.10.102

Works on https://github.com/sourcegraph/security-issues/issues/296.

Test plan

Tested locally via direct ignite calls, and a docker run --rm hello-world within the VM.