feat: update build workflow to trigger on tag pushes for CI validation

Author: afarago

.github/workflows/build.yml

@@ -7,6 +7,9 @@ on:
       - master
       - "feature/**"
       - "feat/**"
+    tags:
+      - "build-test-*"
+      - "v*"
   pull_request:
     branches:
       - master

CHANGELOG.md

@@ -9,6 +9,8 @@ All significant updates to the "blocklypy" extension are tracked in this file.
 - Prepare next release notes.
 - Run VS Code integration tests in GitHub Actions using `xvfb-run` so
   `vscode-test` works in CI headless environments.
+- Run the build workflow on `build-test-*` and `v*` tag pushes for CI
+  validation.
 
 ### Added