fix: eliminate needless lifetimes

[chenrui333]

seeing some regression build issue against rust 1.83.0 as

  error: elided lifetime has a name
    --> src/error.rs:37:39
     |
  37 |     fn source<'a>(&'a self) -> Option<&(dyn error::Error + 'static)> {
     |               --                      ^ this elided lifetime gets resolved as `'a`
     |               |
     |               lifetime `'a` declared here
     |
     = note: `-D elided-named-lifetimes` implied by `-D warnings`
     = help: to override `-D warnings` add `#[allow(elided_named_lifetimes)]`

Status: Ready

relates to Homebrew/homebrew-core#199379

[stepchowfun]

Thank you! I'm not sure why the CI (which has already been updated to use Rust 1.83.0) didn't catch this.

[stepchowfun]

Oh I think I understand why the CI didn't catch this. The CI did catch it in #499, and I had fixed it in a different way by adding the elided lifetime:

fn source<'a>(&'a self) -> Option<&'a (dyn error::Error + 'static)> {

But this fix in this PR (not explicitly quantifying over the lifetime in the first place) is better:

fn source(&self) -> Option<&(dyn error::Error + 'static)> {

So, I think this PR is technically unnecessary; the build should already be passing on the latest commit before this PR. But I think this PR makes the code slightly better!