fix: update Surfer artifact SHA256 (artifact updated on GitLab)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: thomasahle

scripts/toolchain.lock.sh

@@ -11,4 +11,4 @@ readonly CIRCT_REF_LOCKED="6b1f2e8b799352ff3dce2d1ebc6f3eb8f2e360c7"
 readonly CIRCT_LLVM_SUBMODULE_REF_LOCKED="972cd847efb20661ea7ee8982dd19730aa040c75"
 
 readonly SURFER_ARTIFACT_URL_LOCKED="https://gitlab.com/surfer-project/surfer/-/jobs/artifacts/main/download?job=pages_build"
-readonly SURFER_ARTIFACT_SHA256_LOCKED="17b163a919177f2f573bfe3b0021b7328c64908e35a643980b5b06cb1b08469a"
+readonly SURFER_ARTIFACT_SHA256_LOCKED="f2dc43c1b735394e4b153d55bddcad843dade5e39dbfdd0757270e68d19d0fe8"