deps: upgrade to memchr 2.6

We can now utilize its `alloc` feature. And in particular, make the
`Finder::into_owned` API available only when `alloc` is enabled. We
don't need `std` for it, but did previously because `memchr` didn't
expose an `alloc` feature.

Cargo.toml

@@ -24,12 +24,12 @@ bench = false
 [features]
 default = ["std", "unicode"]
 std = ["alloc", "memchr/std", "serde?/std"]
-alloc = ["serde?/alloc"]
+alloc = ["memchr/alloc", "serde?/alloc"]
 unicode = ["dep:regex-automata"]
 serde = ["dep:serde"]
 
 [dependencies]
-memchr = { version = "2.4.0", default-features = false }
+memchr = { version = "2.6.1", default-features = false }
 serde = { version = "1.0.85", default-features = false, optional = true }
 
 [dependencies.regex-automata]

src/ext_slice.rs

@@ -3106,8 +3106,8 @@ impl<'a> Finder<'a> {
     /// If this is already an owned finder, then this is a no-op. Otherwise,
     /// this copies the needle.
     ///
-    /// This is only available when the `std` feature is enabled.
-    #[cfg(feature = "std")]
+    /// This is only available when the `alloc` feature is enabled.
+    #[cfg(feature = "alloc")]
     #[inline]
     pub fn into_owned(self) -> Finder<'static> {
         Finder(self.0.into_owned())
@@ -3189,8 +3189,8 @@ impl<'a> FinderReverse<'a> {
     /// If this is already an owned finder, then this is a no-op. Otherwise,
     /// this copies the needle.
     ///
-    /// This is only available when the `std` feature is enabled.
-    #[cfg(feature = "std")]
+    /// This is only available when the `alloc` feature is enabled.
+    #[cfg(feature = "alloc")]
     #[inline]
     pub fn into_owned(self) -> FinderReverse<'static> {
         FinderReverse(self.0.into_owned())