Overview

Remove the amazon2 variants of the mongot-extension/rerank-extension download targets and the AL2 install-mapping select branches. SERVER-123050 removed the AL2 build variants and the amazon2 entries from etc/extensions.yml, so these targets have been unbuildable dead code since (the download genrule reads its checksum from extensions.yml, which no longer has amazon2 keys). AL2 reached end-of-life in June 2026.

Scope of Work

* src/mongo/db/extension/extensions/BUILD.bazel — drop the amazon2-x86_64/amazon2-aarch64 download genrule variants
* BUILD.bazel — drop the //bazel/config:al2_x86_64/al2_aarch64 extension include_files select branches from both mongo_install targets