Witness generation (ICFP benchmarks, on dev) (#478)

* Use neptune witness-generation.

* Add itcalc example.

* fix: adapt end2end benchmark & associated files

* Refactor version handling and vergen version

- Overhauled the method of obtaining commit date and short sha across files by replacing module functions with environment variables.
- Upgraded the `vergen` dependency from version `0.1` to `8` in `Cargo.toml` and imported limited features.

* fix: restore test_prove_fibonacci

* test: refactor mismatch test utility

* chore:cleanup

---------

Co-authored-by: porcuquine <porcuquine@users.noreply.github.com>

Cargo.toml

@@ -38,6 +38,7 @@ nom = "7.1.3"
 nom_locate = "4.1.0"
 nova = { workspace = true, default-features = false }
 num-bigint = "0.4.3"
+num_cpus = "1.10.1"
 num-integer = "0.1.45"
 num-traits = "0.2.15"
 once_cell = { workspace = true }
@@ -60,6 +61,7 @@ thiserror = { workspace = true }
 camino = { workspace = true }
 abomonation = { workspace = true}
 abomonation_derive = { git = "https://github.com/winston-h-zhang/abomonation_derive.git" }
+crossbeam = "0.8.2"
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 memmap = { version = "0.5.10", package = "memmap2" }
@@ -97,6 +99,7 @@ flamegraph = ["pprof/flamegraph", "pprof/criterion"]
 [dev-dependencies]
 assert_cmd = "2.0.12"
 cfg-if = "1.0.0"
+ascii_table = "4.0.2"
 criterion = "0.4"
 hex = "0.4.3"
 pprof = { version = "0.11" }
@@ -105,6 +108,9 @@ structopt = { version = "0.3", default-features = false }
 tap = "1.0.1"
 tempfile = { workspace = true }
 
+[build-dependencies]
+vergen = { version = "8", features = ["build", "git", "gitcl"] }
+
 [workspace]
 resolver = "2"
 members = [