fix(tedge init): add missing group permissions on base config_dir

[reubenmiller]

Proposed changes

Fix/add group permissions on the config dir (e.g. /etc/tedge) creation when calling the tedge init command.

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Improvement (general improvements like code refactoring that doesn't explicitly fix a bug or add any new functionality)
• Documentation Update (if none of the other choices apply)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Paste Link to the issue

Checklist

• I have read the CONTRIBUTING doc
• I have signed the CLA (in all commits with git commit -s)
• I ran cargo fmt as mentioned in CODING_GUIDELINES
• I used cargo clippy as mentioned in CODING_GUIDELINES
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

Further comments

[codecov]

Codecov Report

Merging #2140 (4c0eb30) into main (08fb053) will decrease coverage by 0.1%.
The diff coverage is 0.0%.

Additional details and impacted files

Files Changed	Coverage Δ
crates/core/tedge/src/cli/init.rs	0.0% <0.0%> (ø)

... and 3 files with indirect coverage changes

[github-actions]

Robot Results

✅ Passed	❌ Failed	⏭️ Skipped	Total	Pass %
247	0	5	247	100

[PradeepKiruvale]

LGTM