pkg/debug: fix riscv build

`abuild -r` fails with:
```
149599 openat(3</>, "lib/apk/db/lock", O_RDWR|O_CREAT|O_CLOEXEC, 0600) =
-1 EACCES (Permission denied)
```

so, let's just build as root to fix this issue

original PR: #5263

How to test and validate this PR

make PLATFORM=generic ZARCH=riscv64 pkg/debug

Changelog notes

Fix riscv build

PR Backports

For all current LTS branches, please state explicitly if this PR should be
backported or not. This section is used by our scripts to track the backports,
so, please, do not omit it.

Here is the list of current LTS branches (it should be always up to date):

• 14.5-stable
• 13.4-stable

For example, if this PR fixes a bug in a feature that was introduced in 14.5,
you can write:

- 14.5-stable: this is the backport
- 13.4-stable: perhaps

Also, to the PRs that should be backported into any stable branch, please
add a label stable.

Checklist

• I've provided a proper description
• I've added the proper documentation
• I've tested my PR on amd64 device
• I've tested my PR on arm64 device
• I've written the test verification instructions
• I've set the proper labels to this PR

For backport PRs (remove it if it's not a backport):

• I've added a reference link to the original PR
• PR's title follows the template

And the last but not least:

• I've checked the boxes above, or I've provided a good reason why I didn't
  check them.

Please, check the boxes above after submitting the PR in interactive mode.