Prepare the 2.9.0.dev1 release.

[benjyw]

[ci skip-rust]

[benjyw]

Internal commits:

• [internal] Make GIL usage explicit for session_poll_workunits (#13609)

• [jvm] Avoid filename collisions for coursier's fetched files (#13607)

• Break repository pex out to its own rule. (#13605)

• [jvm] jvm_artifact targets can specify their packages, and default to owning their group. (#13602)

• [jvm] Support setting additional repositories for coursier (#13606)

• [internal] add append_only_caches to InteractiveProcess (#13591)

• [internal] Switch Rust throw() to use String (#13592)

• [internal] Expose ProcessResult cache source and runtime (#13590)

• [internal] Separate holding of GIL in create_digest_to_digest() (#13586)

• [internal] use f-strings instead of str.format() (#13584)

• [jvm] Finish enabling thirdparty dependency inference for Scala (#13583)

• Prepare 2.8.0rc5. (#13581)

• [jvm] Support mixed-language firstparty inference (#13579)

• Prepare 2.7.2rc2. (#13580)

• [internal] Use pytest's tmp_path fixture in tests (#13575)

• [jvm] UX improvements for compilation and thirdparty dependency lookups (#13573)

• [internal] scala: initial dependency inference support (via explicit imports) (#13569)

• [JVM] Adds enough 3rd-party dependency mappings to compile guice. (#13550)

• Add tailor support for Scala (#13565)

• [internal] Use pytest's tmp_path fixture in test_revision (#13533)

• [internal] Simplify Rust FFI getattr_from_frozendict() (#13564)

• [internal] Remove unused InternType from interning.rs (#13563)

• [internal] scala: extract imports from source files (#13556)

• Java: Handle 3rd-party FQTNs better (#13557)

• Prepare 2.8.0rc4 (#13547)

• Fix formatting of overrides field in docs (#13549)

• [internal] scala: add debug goal to dump source analysis (#13544)

• [internal] java: add debug goal to dump source analysis (#13543)

• [jvm] Add support for consuming types from the unnamed package. (#13536)

• [internal] scala: extract provided names from source files (#13537)

• [jvm] For static imports, drop the last bit of the import name (#13531)

• Go and Java: don't duplicate error logs when dependency failed to compile (#13502)

• [internal] fFx typos (#13517)

• [internal] remove pystache from lockfile (#13532)

• [internal] go: support passing embedcfg to compiler for file embedding (#13509)

• [internal] Use chevron instead of pystache to fix broken release process (#13528)

• Add support for multi-language JVM compilation (#13519)

• [internal] scala: add rules to build and invoke scala parser (#13501)

• [internal] Inline some of externs/mod.rs and make GIL acquisition explicit (#13522)

• [internal] Refactor PyO3 FFI code (#13518)

• [internal] Make explicit when using the GIL with store_* FFI helpers (#13516)

• [internal] Refactor engine_aware.rs to acquire the GIL fewer times (#13515)

• [internal] Refactor TypeId, Key, and Value for rust-cpython FFI (#13514)

• [internal] Upgrade to PyO3 0.15 (#13513)

• Rename old macros to use CAOF (#13511)

• [internal] Rename CompiledClassfiles to ClasspathEntry. (#13508)

• [internal] go: pass -complete flag to compiler(#13507)

• [internal] Always produce/expect jars with scalac (#13506)

• [internal] Refactors to prepare for mixed jvm compilation (#13500)

• [internal] Add a NOTE to requirements.txt (#13498)

• Prepare 2.8.0rc3 (#13495)

• [internal] go: analyze go:embed patterns (#13489)

• [internal] Log Go first-party analysis at DEBUG level (#13487)

• fs_util: Allow setting headers (#13484)