fix(docker): upgrade Alpine packages to address CVE-2025-15467

[juanfe2793]

Add step to the Dockerfile to ensure all base Alpine packages are updated to their latest versions. This fixes a critical OpenSSL vulnerability (CVE-2025-15467) in libssl3 and libcrypto3 that has a public exploit available.

• libssl3: 3.5.0-r0 → 3.5.5-r0
• libcrypto3: 3.5.0-r0 → 3.5.5-r0

Reference: https://security.alpinelinux.org/vuln/CVE-2025-15467

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This is my first PR contributing to Kong Deck, I appreciate the guidance into the right process for this type of security patches.

[CLAassistant]

All committers have signed the CLA.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 33.54%. Comparing base (efa9eef) to head (9aa70ec).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1923      +/-   ##
==========================================
- Coverage   33.58%   33.54%   -0.05%     
==========================================
  Files          76       76              
  Lines        6711     6711              
==========================================
- Hits         2254     2251       -3     
- Misses       4278     4280       +2     
- Partials      179      180       +1     

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[Prashansa-K]

EE and Konnect testing won't be possible here as this branch came from a fork.
The changes submitted don't need those particular tests as well.

OSS and Aikido checks are green.

Allowing this PR.

[Prashansa-K]

Thanks for the contribution @juanfe2793!