subscriber: revert "subscriber: update time crate to 0.3.18 (#2550)"

This reverts commit 9744ec0. This
change breaks MSRV compatibility, and was accidentally auto-merged due
to what appears to be an issue with the CI configuration, which
(apparently) doesn't require the MSRV minimal-versions check runs to
complete before allowing a branch to merge.

We'll have to solve the original issue here through documentation for
now. See [this comment] for details.

[this comment]: #2550 (comment)

tracing-subscriber/src/fmt/time/time_crate.rs

@@ -13,16 +13,14 @@ use time::{format_description::well_known, formatting::Formattable, OffsetDateTi
 ///     local timestamps. When this cfg is not enabled, local timestamps cannot be recorded, and
 ///     events will be logged without timestamps.
 ///
-///    Alternatively, [`OffsetTime`] can log with a local offset if it is initialized early.
-///
 ///    See the <a href="https://docs.rs/time/0.3.4/time/#feature-flags"><code>time</code>
 ///    documentation</a> for more details.
 /// </pre></div>
 ///
-/// [local time]: time::OffsetDateTime::now_local
-/// [UTC time]:     time::OffsetDateTime::now_utc
-/// [formatter]:    time::formatting::Formattable
-/// [`time` crate]: time
+/// [local time]: https://docs.rs/time/0.3/time/struct.OffsetDateTime.html#method.now_local
+/// [UTC time]: https://docs.rs/time/0.3/time/struct.OffsetDateTime.html#method.now_utc
+/// [formatter]: https://docs.rs/time/0.3/time/formatting/trait.Formattable.html
+/// [`time` crate]: https://docs.rs/time/0.3/time/
 #[derive(Clone, Debug)]
 #[cfg_attr(
     docsrs,