Refine 0.31.1 changelog

Keep the patch release notes focused on user-facing fixes.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: wenytang-ms

CHANGELOG.md

@@ -5,8 +5,6 @@
 - Add Content Security Policy to webviews in https://github.com/microsoft/vscode-java-pack/pull/1648
 - Fix Project Settings dropdown updates in https://github.com/microsoft/vscode-java-pack/pull/1655
 - Bundle the codicon font in the Java Help Center webview in https://github.com/microsoft/vscode-java-pack/pull/1658
-- Exclude E2E test fixtures, test plans, and generated test results from the VSIX package in https://github.com/microsoft/vscode-java-pack/pull/1659
-- Update dependencies and build tooling.
 
 ## 0.31.0