fix(contracts): OZ-N01 Variable Cast is Unnecessary

[zimpha]

Purpose or design rationale of this PR

This PR partially fixed the issue reported by Openzepplin (N-01 Variable Cast is Unnecessary) during ScrollOwner and Rate Limiter audit. The following are the details:

Within the ScrollOwner contract, the _target variable in the _execute function was unnecessarily cast.

To improve the overall clarity, intent, and readability of the codebase, consider removing this unnecessary cast.

PR title

Your PR title must follow conventional commits (as we are doing squash merge for each PR), so it must start with one of the following types:

• fix: A bug fix

Deployment tag versioning

Has tag in common/version.go been updated or have you added bump-version tag to this PR?

• No, this PR doesn't involve a new deployment, git tag, docker image tag
• Yes

Breaking change label

Does this PR have the breaking-change label?

• No, this PR is not a breaking change
• Yes

[github-actions]

LCOV of commit e4f6895 during Contracts #1372

Summary coverage rate:
  lines......: 52.6% (992 of 1885 lines)
  functions..: 67.3% (222 of 330 functions)
  branches...: no data found

Files changed coverage rate: n/a