Update submodules

[Alan-Jowett]

This pull request includes updates to several submodules and changes to the libfuzzer harness to improve the verifier options configuration. The most important changes include updating submodule commits and modifying the verifier options to use a more structured approach.

Submodule updates:

• external/bpf_conformance: Updated the submodule commit to the latest version.
• external/ebpf-verifier: Updated the submodule commit to the latest version.

Verifier options configuration:

• libfuzzer/libfuzz_harness.cc: Changed the initialization of ebpf_verifier_options_t to use an empty initializer list. Modified the options to enable termination checking and disable simplification through cfg_opts. Simplified the call to ebpf_verify_program by passing options directly.

[coveralls]

coverage: 79.201%. remained the same when pulling 80d7d7ceed75e71acecb6a785923b2b4bd5e0af9 on Alan-Jowett:update into 24087eb5c00c0e581b61bacb10514de1a50bae1e on iovisor:main.