Bump diesel to 2.3.7 and diesel-dtrace to 0.5.0.

[mergeconflict]

This dependency version bump is in preparation for bumping the rust toolchain to 1.94.0 (#10058). Without it, we get some compiler warnings about conflicting min symbols imported from diesel:

warning: `min` is ambiguous
   --> nexus/db-queries/src/db/datastore/ereport.rs:22:35
    |
 22 | use diesel::dsl::{count_distinct, min};
    |                                   ^^^ ambiguous name
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #114095 <https://github.com/rust-lang/rust/issues/114095>
    = note: ambiguous because of multiple glob imports of a name in the same module
note: `min` could refer to the type alias defined here
   --> /Users/dr/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/diesel-2.2.12/src/lib.rs:319:13
    |
319 |     pub use crate::helper_types::*;
    |             ^^^^^^^^^^^^^^^^^^^
    = help: consider updating this dependency to resolve this error
    = help: if updating the dependency does not resolve the problem report the problem to the author of the relevant crate
note: `min` could also refer to the type alias defined here
   --> /Users/dr/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/diesel-2.2.12/src/lib.rs:322:13
    |
322 |     pub use crate::expression::dsl::*;
    |             ^^^^^^^^^^^^^^^^^^^^^^
    = note: `#[warn(ambiguous_glob_imports)]` (part of `#[warn(future_incompatible)]`) on by default

Also replace deprecated diesel::dsl::count_distinct() with count().aggregate_distinct() from AggregateExpressionMethods.