The real reason for #2165

There are many cases pgrx can benefit from let-chains.
Format the world to allow using Edition 2024.

NOTE: This is, strictly speaking, a breaking change because bindgen will
alter the name for the `gen` field on certain structs to `gen_`.

…#2169)

The real reason for pgcentralfoundation#2165

Welcome to pgrx v0.17.0. This is a new minor release that brings a bunch
of internal code refactoring, cleanup, new Postgres headers, and
additional `cargo-pgrx regress` CLI options.

As always, please install the latest `cargo-pgrx` with `cargo install
cargo-pgrx --version 0.17.0 --locked` and also update your extension
crate dependencies with `cargo pgrx upgrade`.

## What's Changed


### New Headers/Symbols

* include `access/tsmapi.h` by @usamoi in
#2155
* Include access/subtrans.h & access/commit_ts.h by @isdaniel in
#2147
* include `utils/guc_tables.h` by @usamoi in
#2243
* Include `scanner.h` in Rust bindings by @piki in
#2163
* Add `commands/publicationcmds.h` to generated `pg_sys` bindings by
@Sinjo in #2221
* Add the ClientAuthentication_hook by @daamien in
#2231
* add storage/dsm_*.h headers by @eeeebbbbrrrr in
#2244
* pg-sys: add catalog/heap.h bindings for PG18 by @charmitro in
#2150
* Add back `peer_dn` field to `Port` on `pg17..` by @workingjubilee in
#2200
* Add `repr(C)` to `struct Port` on `pg13..=16` by @workingjubilee in
#2201

### `cargo-pgrx` improvements

* Add a psql_verbosity parameter for cargo pgrx regress by @daamien in
#2230


### Code Cleanup

* Replace with let-chains in pgrx-bindgen by @workingjubilee in
#2168
* Replace with let-chains in pgrx-sql-entity-graph by @workingjubilee in
#2169
* Restore so-called needless lifetimes by @workingjubilee in
#2167
* Drop stray Postgres 12 support in cargo-pgrx by @workingjubilee in
#2173
* Remove deprecated enum##member constants by @workingjubilee in
#2170
* Remove `variadic!` macro by @workingjubilee in
#2171
* Semi-automated code cleanup by @workingjubilee in
#2189
* Deref instead of borrowing `Option<&String>` by @workingjubilee in
#2185
* Refactor schema.rs using a cargo command builder by @workingjubilee in
#2187
* Replace `impl AsRef<T>` with `&T` by @workingjubilee in
#2182
* Make `PgRelation::heap_relation` unsafe by @workingjubilee in
#2176
* Move `cargo_pgrx::env` to `cargo_pgrx::cargo` by @workingjubilee in
#2186
* Move `CargoProfile` into `cargo_pgrx::cargo` by @workingjubilee in
#2188
* Add Scalar trait for generic handling of primitive arrays by
@workingjubilee in #2153
* Set BGWORKER_SHMEM_ACCESS when building background workers by @cbandy
in #2161
* Stop referencing `pg_config` in schema generation by @workingjubilee
in #2174
* Show line number of failed asserts by @piki in
#2175
* Ghostbust `used_type.rs` a bit by @workingjubilee in
#2190
* Manually bind `static MyProcPort` and `struct Port` by @workingjubilee
in #2162
* Make datetime types import each other via `use super` by
@workingjubilee in #2198
* Migrate datetime types into `pgrx::datetime` by @workingjubilee in
#2199
* Use diagnostic attrs for ABI/SQL-related traits by @workingjubilee in
#2203
* Make `Scalar` provide `pg_sys::Oid` constant by @workingjubilee in
#2209
* Hoist varlena encoding fn by @workingjubilee in
#2208
* Recurse through `T` while anonymizing `&T` by @workingjubilee in
#2212
* `impl BorrowDatum for TimeTz` by @workingjubilee in
#2213
* Change `MemCx::alloc_bytes` to return `NonNull` by @workingjubilee in
#2214
* Add `MemCx<'current, T>` arguments and `PBox<'current, T>` returns by
@workingjubilee in #2210
* Further improve diagnostics for signatures with no SQL form by
@workingjubilee in #2215
* Add `array::Element` and `callconv::DatumPass` by @workingjubilee in
#2218
* Remove unused line in `memcxt_tests.rs` by @workingjubilee in
#2220
* Add `FlatArray<'_, T>` by @workingjubilee in
#2207
* Allow explicit handling of allocation errors by @workingjubilee in
#2226
* Place lbound before updating array len product by @workingjubilee in
#2236
* introduce `#[pg_guard(unsafe_entry_thread)]` by @eeeebbbbrrrr in
#2242


### Project Administrativa 

* Use Rust Edition 2024 by @workingjubilee in
#2165
* Remove testing for deprecated Intel Macs by @workingjubilee in
#2156
* Remove unused Cargo.lock for version-updater by @workingjubilee in
#2180
* Add rust-analyzer.toml by @workingjubilee in
#2179
* Note pgrx requires an unknown minimum Xcode version by @workingjubilee
in #2164

## New Contributors

* @isdaniel made their first contribution in
#2147
* @cbandy made their first contribution in
#2161
* @piki made their first contribution in
#2163
* @Sinjo made their first contribution in
#2221

**Full Changelog**:
v0.16.1...v0.17.0