Remove Antithesis docker build workflow (#4642)

## Issue Addressed

This PR remove Antithesis docker build CI workflow. Confirmed with Antithesis team that this is no longer used.

testing/antithesis/Dockerfile.libvoidstar

@@ -1,25 +0,0 @@
-FROM rust:1.68.2-bullseye AS builder
-RUN apt-get update && apt-get -y upgrade && apt-get install -y cmake libclang-dev
-COPY . lighthouse
-
-# Build lighthouse directly with a cargo build command, bypassing the Makefile.
-RUN cd lighthouse && LD_LIBRARY_PATH=/lighthouse/testing/antithesis/libvoidstar/ RUSTFLAGS="-Cpasses=sancov-module -Cllvm-args=-sanitizer-coverage-level=3 -Cllvm-args=-sanitizer-coverage-trace-pc-guard -Ccodegen-units=1 -Cdebuginfo=2 -L/lighthouse/testing/antithesis/libvoidstar/ -lvoidstar" cargo build --release --manifest-path lighthouse/Cargo.toml --target x86_64-unknown-linux-gnu --features modern --verbose --bin lighthouse
-# build lcli binary directly with cargo install command, bypassing the makefile
-RUN cargo install --path /lighthouse/lcli --force --locked
-
-FROM ubuntu:latest
-RUN apt-get update && apt-get -y upgrade && apt-get install -y --no-install-recommends \
-  libssl-dev \
-  ca-certificates \
-  && apt-get clean \
-  && rm -rf /var/lib/apt/lists/*
-
-# create and move the libvoidstar file
-RUN mkdir libvoidstar
-COPY --from=builder /lighthouse/testing/antithesis/libvoidstar/libvoidstar.so /usr/lib/libvoidstar.so
-
-# set the env variable to avoid having to always set it
-ENV LD_LIBRARY_PATH=/usr/lib
-# move the lighthouse binary and lcli binary
-COPY --from=builder /lighthouse/target/x86_64-unknown-linux-gnu/release/lighthouse /usr/local/bin/lighthouse
-COPY --from=builder  /lighthouse/target/release/lcli /usr/local/bin/lcli