Remove trailing semicolons from macro bodies

[Tiwalun]

clippy from cargo 1.99.0-beta.6 includes a new lint, which triggers on trailing semicolon in expression macro bodies.

Code like this:

#[test]
fn it_works() {
  insta::assert_json_snapshot!("a")
}

leads to this clippy warning:

warning: trailing semicolon in macro used in expression position
  --> src/lib.rs:10:9
   |
10 |         insta::assert_json_snapshot!("a")
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: macro invocations at the end of a block are treated as expressions
   = note: to ignore the value produced by the macro, add a semicolon after the invocation of `assert_json_snapshot`
   = 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 #79813 <https://github.com/rust-lang/rust/issues/79813>
   = note: `#[warn(semicolon_in_expressions_from_non_local_macros)]` (part of `#[warn(future_incompatible)]`) on by default
   = note: this warning originates in the macro `insta::assert_json_snapshot` (in Nightly builds, run with -Z macro-backtrace for more info)

This change removes these semicolons.

Looking at the output of cargo-expand, the final code doesn't seem to change, so this shouldn't have

See rust-lang/rust#79813.

[nyurik]

@max-sixty thx for merging - would it be possible to release it? Thx!