fix(deps): pin next to 16.1.5 to avoid bun crash in docker build

Next.js 16.3.0 triggers a segmentation fault (SIGILL) in Bun 1.3.14 on Linux x64 during worker teardown at the end of `next build`, causing CI deployments to fail with exit code 132.

Downgrade next, @next/third-parties and eslint-config-next to the last known-good versions until Bun ships a fix.

Author: JeffreyArt1