CI/CD improvements

[azkrishpy]

Issue #, if available:

N/A

Description of changes:

Adds CI/CD workflows mirroring awslabs/aws-c-common#1250:

• check-abi.yml — ABI compliance check on PRs
• release.yml — manual (workflow_dispatch) release with auto version bump + tag
• block-needs-review.yml — gate merges labeled needs-review
• VERSION file seeded from latest release tag
• CMakeLists.txt: derive target VERSION from VERSION file via aws_get_version()

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.61%. Comparing base (e35b9ca) to head (2e7d491).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #434      +/-   ##
==========================================
- Coverage   84.65%   84.61%   -0.05%     
==========================================
  Files          26       26              
  Lines       11093    11109      +16     
==========================================
+ Hits         9391     9400       +9     
- Misses       1702     1709       +7     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.