chore: golangcilint update

[ivokub]

Description

Update golangci-lint version in CI. Also fix errors found by new linter.

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Note

Medium Risk
Medium risk because it changes P-256 hint/table generation from crypto/elliptic to gnark-crypto (could affect curve scalar-mul results) alongside CI/lint upgrades; remaining changes are mostly tooling and lint suppressions.

Overview
CI/tooling: Updates PR/push workflows to pin GitHub Actions versions/SHAs, centralize abigen/golangci-lint versions via env vars, and bump golangci-lint to v2.10.1.

Crypto/emulated curves: Reworks P-256 (secp256r1) scalar-mul hint and precomputed table generation to use gnark-crypto (secp256r1) instead of crypto/elliptic, and adds targeted nolint annotations (including staticcheck for remaining P-384 crypto/elliptic usage and gosec for Public/Secret wire-name fields). Also bumps the module go version from 1.25.6 to 1.25.7.

^{Written by Cursor Bugbot for commit 1226146. This will update automatically on new commits. Configure here.}