chore: update CentOS Linux 7 mirror to vault

[Venefilyn]

With CentOS Linux 7 now being unsupported the packages were moved to the vault as it is no longer recommended to use

Jira Issues:

-

Checklist

• [ ] PR has been tested manually in a VM (either author or reviewer)
• [ ] Jira issue has been made public if possible
• [ ] [RHELC-] or [HMS-] is part of the PR title
• [ ] GitHub label has been added to help with Release notes
• [ ] PR title explains the change from the user's point of view
• [ ] Code and tests are documented properly
• [ ] The commits are squashed to as few commits as possible (without losing data)
• [ ] When merged: Jira issue has been updated to Release Pending if relevant

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 95.83%. Comparing base (5c42c1f) to head (6c09c71).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1294 +/- ## ======================================= Coverage 95.83% 95.83% ======================================= Files 55 55 Lines 4756 4756 Branches 836 836 ======================================= Hits 4558 4558 Misses 112 112 Partials 86 86 ``` | [Flag](https://app.codecov.io/gh/oamg/convert2rhel/pull/1294/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=oamg) | Coverage Δ | | |---|---|---| | [centos-linux-7](https://app.codecov.io/gh/oamg/convert2rhel/pull/1294/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=oamg) | `91.02% <ø> (ø)` | | | [centos-linux-8](https://app.codecov.io/gh/oamg/convert2rhel/pull/1294/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=oamg) | `91.95% <ø> (ø)` | | | [centos-linux-9](https://app.codecov.io/gh/oamg/convert2rhel/pull/1294/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=oamg) | `92.00% <ø> (ø)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=oamg#carryforward-flags-in-the-pull-request-comment) to find out more.

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[has-bot]

This PR does not require integration tests to be run.

---

Comment generated by an automation.

Log | Bot Usage

[bocekm]

There are no CentOS-Linux-* repofiles on CentOS Linux 7:

# ll /etc/yum.repos.d/
-rw-r--r--. 1 root root 1664 May 21 10:48 CentOS-Base.repo
-rw-r--r--. 1 root root 1309 May 21 10:48 CentOS-CR.repo
-rw-r--r--. 1 root root  649 May 21 10:48 CentOS-Debuginfo.repo
-rw-r--r--. 1 root root  314 May 21 10:48 CentOS-fasttrack.repo
-rw-r--r--. 1 root root  630 May 21 10:48 CentOS-Media.repo
-rw-r--r--. 1 root root 1331 May 21 10:48 CentOS-Sources.repo
-rw-r--r--. 1 root root 9454 May 21 10:48 CentOS-Vault.repo
-rw-r--r--. 1 root root  616 May 21 10:48 CentOS-x86_64-kernel.repo