added timeouts + dropped prev vscode version due to build issues

[siddhusaladi]

• Drop previous from the VS Code matrix for CI because cold previous version runners can cause Liberty LS JVM startup times of 5–7 minutes per workspace transition, exceeding any reasonable test timeout
• Bump before(src/test/shared/devModeTestSuite.ts), afterEach(src/test/shared/devModeTestSuite.ts), and after hook(in devModeActions tests) timeouts
• waitForDashboardToLoad (src/test/utils/testUtils.ts) timeout increased from 120s to 180s
• Fresh SideBarView created on each poll in getDashboardSection to prevent stale DOM errors during workspace transitions between tests