Remove redundant format Make targets (#724)

Just use `cargo fmt` or `cargo fmt --all` for the same effect.

Especially the `fmt` target was obsolote: why would you want to format
specifically only `ceno_zkvm`?

.github/workflows/lints.yml

@@ -63,7 +63,7 @@ jobs:
         run: |
           cargo make --version || cargo install cargo-make
       - name: Check code format
-        run: cargo make fmt-all-check
+        run: cargo fmt --all --check
 
       - name: Run clippy
         env:

Makefile.toml

@@ -33,26 +33,11 @@ args = [
 command = "cargo"
 workspace = false
 
-[tasks.fmt-all-check]
-args = ["fmt", "--all", "--", "--check"]
-command = "cargo"
-workspace = false
-
-[tasks.fmt-all]
-args = ["fmt", "--all"]
-command = "cargo"
-workspace = false
-
 [tasks.clippy-all]
 args = ["clippy", "--all-features", "--all-targets", "--", "-D", "warnings"]
 command = "cargo"
 workspace = false
 
-[tasks.fmt]
-args = ["fmt", "-p", "ceno_zkvm", "--", "--check"]
-command = "cargo"
-workspace = false
-
 [tasks.riscv_stats]
 args = ["run", "--bin", "riscv_stats"]
 command = "cargo"