Remove unused member functions from deque_anchor

Starting with clang 19, the unused member functions cas that take a deque_anchor fail to compile
because they attempt to call load directly on the deque_anchor type, whereas they should be calling
load on the atomic stored in the deque_anchor. Neither GCC nor clang until version 18 failed to
compile the broken member functions (because they were unused they were never instantiatied). Since
the functions are unused, simply remove them.

Related llvm issue: llvm/llvm-project#102177.

libs/pika/concurrency/include/pika/concurrency/deque.hpp

@@ -123,47 +123,6 @@ namespace pika::concurrency::detail {
 
         pair lrs(std::memory_order mo = std::memory_order_acquire) const { return pair_.load(mo); }
 
-        node* left(std::memory_order mo = std::memory_order_acquire) const
-        {
-            return pair_.load(mo).get_left_ptr();
-        }
-
-        node* right(std::memory_order mo = std::memory_order_acquire) const
-        {
-            return pair_.load(mo).get_right_ptr();
-        }
-
-        tag_t status(std::memory_order mo = std::memory_order_acquire) const
-        {
-            return pair_.load(mo).get_left_tag();
-        }
-
-        tag_t tag(std::memory_order mo = std::memory_order_acquire) const
-        {
-            return pair_.load(mo).get_right_tag();
-        }
-
-        bool cas(deque_anchor& expected, deque_anchor const& desired,
-            std::memory_order mo = std::memory_order_acq_rel)
-        {
-            return pair_.compare_exchange_strong(expected.load(std::memory_order_acquire),
-                desired.load(std::memory_order_acquire), mo);
-        }
-
-        bool cas(pair& expected, deque_anchor const& desired,
-            std::memory_order mo = std::memory_order_acq_rel)
-        {
-            return pair_.compare_exchange_strong(
-                expected, desired.load(std::memory_order_acquire), mo);
-        }
-
-        bool cas(deque_anchor& expected, pair const& desired,
-            std::memory_order mo = std::memory_order_acq_rel)
-        {
-            return pair_.compare_exchange_strong(
-                expected.load(std::memory_order_acquire), desired, mo);
-        }
-
         bool cas(
             pair& expected, pair const& desired, std::memory_order mo = std::memory_order_acq_rel)
         {