Temporarily move clippy::unused_peekable to nursery

src/tools/clippy/clippy_lints/src/lib.register_all.rs

@@ -344,7 +344,6 @@
     LintId::of(unnecessary_owned_empty_strings::UNNECESSARY_OWNED_EMPTY_STRINGS),
     LintId::of(unsafe_removed_from_name::UNSAFE_REMOVED_FROM_NAME),
     LintId::of(unused_io_amount::UNUSED_IO_AMOUNT),
-    LintId::of(unused_peekable::UNUSED_PEEKABLE),
     LintId::of(unused_unit::UNUSED_UNIT),
     LintId::of(unwrap::PANICKING_UNWRAP),
     LintId::of(unwrap::UNNECESSARY_UNWRAP),

src/tools/clippy/clippy_lints/src/lib.register_nursery.rs

@@ -31,6 +31,7 @@
     LintId::of(suspicious_operation_groupings::SUSPICIOUS_OPERATION_GROUPINGS),
     LintId::of(trailing_empty_array::TRAILING_EMPTY_ARRAY),
     LintId::of(transmute::TRANSMUTE_UNDEFINED_REPR),
+    LintId::of(unused_peekable::UNUSED_PEEKABLE),
     LintId::of(unused_rounding::UNUSED_ROUNDING),
     LintId::of(use_self::USE_SELF),
 ])

src/tools/clippy/clippy_lints/src/lib.register_suspicious.rs

@@ -35,6 +35,5 @@
     LintId::of(suspicious_trait_impl::SUSPICIOUS_ARITHMETIC_IMPL),
     LintId::of(suspicious_trait_impl::SUSPICIOUS_OP_ASSIGN_IMPL),
     LintId::of(swap_ptr_to_ref::SWAP_PTR_TO_REF),
-    LintId::of(unused_peekable::UNUSED_PEEKABLE),
     LintId::of(write::POSITIONAL_NAMED_FORMAT_PARAMETERS),
 ])

src/tools/clippy/clippy_lints/src/unused_peekable.rs

@@ -38,7 +38,7 @@
     /// ```
     #[clippy::version = "1.64.0"]
     pub UNUSED_PEEKABLE,
-    suspicious,
+    nursery,
     "creating a peekable iterator without using any of its methods"
 }