[fix](memory) Process available memory to increase the Jemalloc cache (…

…#45621)

### What problem does this PR solve?

Currently, when the Doris BE process exceed memory limit, Jemalloc cache
will be manually released.
Add the Jemalloc cache to the available memory of the BE process is
expected to have little impact on the risk of the process OOM killer.
the process memory used has already subtracted the Jemalloc cache.

Not merge to 2.1 because 2.1 is stable now

be/src/runtime/memory/global_memory_arbitrator.h

@@ -76,7 +76,7 @@ class GlobalMemoryArbitrator {
     static inline int64_t sys_mem_available() {
         return MemInfo::_s_sys_mem_available.load(std::memory_order_relaxed) -
                refresh_interval_memory_growth.load(std::memory_order_relaxed) -
-               process_reserved_memory();
+               process_reserved_memory() + static_cast<int64_t>(MemInfo::allocator_cache_mem());
     }
 
     static inline std::string sys_mem_available_str() {
@@ -91,12 +91,14 @@ class GlobalMemoryArbitrator {
     static inline std::string sys_mem_available_details_str() {
         auto msg = fmt::format(
                 "sys available memory {}(= {}[proc/available] - {}[reserved] - "
-                "{}B[waiting_refresh])",
+                "{}B[waiting_refresh] + {}[tc/jemalloc_cache])",
                 PrettyPrinter::print(sys_mem_available(), TUnit::BYTES),
                 PrettyPrinter::print(MemInfo::_s_sys_mem_available.load(std::memory_order_relaxed),
                                      TUnit::BYTES),
                 PrettyPrinter::print(process_reserved_memory(), TUnit::BYTES),
-                refresh_interval_memory_growth);
+                refresh_interval_memory_growth,
+                PrettyPrinter::print(static_cast<uint64_t>(MemInfo::allocator_cache_mem()),
+                                     TUnit::BYTES));
 #ifdef ADDRESS_SANITIZER
         msg = "[ASAN]" + msg;
 #endif