Bump Gradle API Version

This skill walks through bumping GradlePluginVariant.GRADLE_COMMON_COMPILE_API_VERSION — the Gradle API version that the Kotlin Gradle plugins' common source set is compiled against.

IMPORTANT: This project uses JetBrains MCP tools for all file operations. Use mcp__idea__* tools (read_file, replace_text_in_file, search_in_files_by_text, etc.) instead of standard Read/Edit/Grep/Glob tools.

Step 1 — Confirm the target version

If the user hasn't specified the target Gradle API version, ask them for it before proceeding.

Read the current value from:

repo/gradle-build-conventions/gradle-plugins-common/src/main/kotlin/gradle/GradlePluginVariant.kt