fix(l1,l2): add feature flag to decide precompute number

[tomip01]

Motivation

Risc0 is currently failing because precompute must be set to 0.

This changes were made by @gianbelinche

Follow up

Opened this issue to update the code once the change becomes available.

[Copilot]

Pull Request Overview

This PR introduces a feature flag system to conditionally set the KZG precompute parameter based on the target environment. It addresses Risc0 compatibility issues by setting the precompute value to 0 for Risc0 builds while maintaining the optimized value of 8 for other environments.

• Added a risc0 feature flag across the common crates
• Introduced conditional compilation for KZG precompute values
• Updated all KZG function calls to use the new configurable constant

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
crates/l2/prover/src/guest_program/src/risc0/Cargo.toml	Enables the risc0 feature for ethrex-common dependency
crates/common/crypto/kzg.rs	Adds conditional KZG_PRECOMPUTE constant and updates function calls
crates/common/crypto/Cargo.toml	Defines the risc0 feature flag
crates/common/Cargo.toml	Propagates the risc0 feature to the crypto subcrate

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[github-actions]

Lines of code report

Total lines added: 6
Total lines removed: 0
Total lines changed: 6

Detailed view

+------------------------------------+-------+------+
| File                               | Lines | Diff |
+------------------------------------+-------+------+
| ethrex/crates/common/crypto/kzg.rs | 143   | +6   |
+------------------------------------+-------+------+

[ilitteri]

Let's include c-kzg in risc0.

[tomip01]

Done 2c5b849

[ilitteri]

Don't we need to update RISC0's guest Cargo.lock?

[tomip01]

No, there is no need. I ran cargo check inside risc0 guest program and nothing change