Prepare documentation for v6 release (actions#1253)

Update public examples and release messaging to make v6 the recommended stable version, include late-cycle v6 features, and increase the JetBrains test timeout to avoid cold-run flakes.

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

Copilot-Session: 24e3d384-3bda-4ca3-b1fc-f49e340c174f

Prepare documentation for v6 release (actions#1253)

Update public examples and release messaging to make v6 the recommended stable version, include late-cycle v6 features, and increase the JetBrains test timeout to avoid cold-run flakes.

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

Copilot-Session: 24e3d384-3bda-4ca3-b1fc-f49e340c174f

Deprecate setup-java v4 (actions#1194)

Add a deprecation message to the v4 action metadata and emit a runtime warning that v4 will no longer receive updates, directing users to migrate to setup-java v5.

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

Copilot-Session: c8931f2e-fb40-497a-b529-be37cb97a0ae

Deprecate setup-java v4 (actions#1194)

Add a deprecation message to the v4 action metadata and emit a runtime warning that v4 will no longer receive updates, directing users to migrate to setup-java v5.

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

Copilot-Session: c8931f2e-fb40-497a-b529-be37cb97a0ae

Deprecate setup-java v3 (actions#1195)

Add a deprecation message to the v3 action metadata and emit a runtime warning that v3 will no longer receive updates, directing users to migrate to setup-java v5.

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

Deprecate setup-java v3 (actions#1195)

Add a deprecation message to the v3 action metadata and emit a runtime warning that v3 will no longer receive updates, directing users to migrate to setup-java v5.

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

Deprecate setup-java v2 (actions#1196)

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

Deprecate setup-java v2 (actions#1196)

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

Deprecate setup-java v1 (actions#1197)

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

Deprecate setup-java v1 (actions#1197)

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