bug: Improve style consistency of Bluesky SVG icon

[dabikuru]

What does this PR change? What problem does it solve?
Change the fill of the Bluesky icon from solid to outline, to match the style of other social icons. I have achieved that with a small SVG change to the existing icon, rather than replacing it with an icon from a different source.

Before:

After:

Was the change discussed in an issue or in the Discussions before?

PR Checklist

Closes #1654

• This change adds/updates translations and I have used the template present here.
• I have enabled maintainer edits for this PR.
• I have verified that the code works as described/as intended.
• This change adds a Social Icon which has a permissive license to use it.
• This change does not include any CDN resources/links.
• This change does not include any unrelated scripts such as bash and python scripts.
• This change updates the overridden internal templates from HUGO's repository.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud