Fix two broken CONTRIBUTING.md links in the pre-work issue template

### Overview

We need to correct two links in the pre-work issue template that point to the wrong place in `CONTRIBUTING.md`, so new members aren't sent to a dead or incorrect section on their first day. One anchor doesn't exist at all, and the other silently scrolls to the wrong section.

### Action Items

- [ ] In `.github/ISSUE_TEMPLATE/pre-work-template-devops-security.md` line 29, change the "Login as root user & setup MFA" link anchor from `#login-as-root-user-&-setup-mfa` to `#login-as-root-user--setup-mfa`. GitHub strips `&` when generating heading anchors, which leaves two hyphens.
- [ ] On line 31, change the "Creating an IAM User" link anchor from `#create-an-iam-group` to `#create-an-iam-user`. Line 32 ("Creating an IAM Group") already points at `#create-an-iam-group` correctly and should be left alone.
- [ ] Open the rendered `CONTRIBUTING.md` and confirm both links now scroll to their matching sections.

### Resources/Instructions

- File to change: [pre-work-template-devops-security.md](https://github.com/hackforla/devops-security/blob/main/.github/ISSUE_TEMPLATE/pre-work-template-devops-security.md) (lines 29 and 31)
- Target document: [CONTRIBUTING.md](https://github.com/hackforla/devops-security/blob/main/CONTRIBUTING.md)
- **Line numbers were accurate when this issue was written and may drift as the file is edited.** If they no longer match, find the links by their link text ("Login as root user & setup MFA" and "Creating an IAM User") rather than by line number.
- The anchors are valid; only these two links are wrong. The other four `CONTRIBUTING.md` links in the template were checked and are correct.
- Both target headings are written as list items (`- ### **Create an IAM User**`). GitHub still generates anchors for these, so no change to `CONTRIBUTING.md` is needed.
- [GitHub docs: section links and heading anchors](https://docs.github.com/en/get-started/writing-on-github/getting-started-with-writing-and-formatting-on-github/basic-writing-and-formatting-syntax#section-links)
- Note: pre-work issues already opened keep the old links; only newly created ones pick up the fix.

Open .github/ISSUE_TEMPLATE/pre-work-template-devops-security.md and locate the links by their text if the listed lines have shifted. Compare the two anchors with the matching headings in the rendered CONTRIBUTING.md, update only those links, and confirm both now scroll to the correct sections; leave the IAM Group link unchanged.

索引モデルが issue の本文から書いたものです。