Remove gimli-symbolize crate feature

CHANGELOG.md

@@ -10,6 +10,7 @@ All notable changes to this project will be documented in this file.
   - This may be API breaking when users use `default-features = false` so that `&backtrace::Backtrace` doesn't coerce to `&dyn Backtrace`
 - Add experimental support for `std::backtrace::Backtrace`
   - Enable via `{ default-features = false, features = ["use-btparse-crate"] }`
+- Removed previously deprecated `gimli-symbolize` crate feature
 
 ## [v0.6.1] (2023-10-23)
 - Publicly expose some helper methods on `Frame` type

Cargo.toml

@@ -24,9 +24,6 @@ use-backtrace-crate = ["dep:backtrace"]
 # Not guaranteed to work if Rust decides to change the format, but fewer dependencies.
 use-btparse-crate = ["dep:btparse"]
 
-# Deprecated, no longer has any effect: backtrace crate removed corresponding option.
-gimli-symbolize = []
-
 [dependencies]
 termcolor = "1.1.2"
 backtrace = { version = "0.3.57", optional = true }