Use atomics in trackingAlloc()

[ldorau]

Use utils_atomic_store_release_ptr() atomics in trackingAlloc().

It fixes a data race detected by TSAN:
https://github.com/ldorau/unified-memory-framework/actions/runs/14440708601/job/40490018118

WARNING: ThreadSanitizer: data race (pid=85235)
  Write of size 8 at 0x7f5ae5e5c6e8 by thread T18 (mutexes: write M0):
    #0 trackingAlloc /home/runner/work/unified-memory-framework/unified-memory-framework/src/provider/provider_tracking.c:474 (test_memoryPool+0xb1b53)
    #1 umfMemoryProviderAlloc /home/runner/work/unified-memory-framework/unified-memory-framework/src/memory_provider.c:245 (test_memoryPool+0xada4d)
    #2 create_slab /home/runner/work/unified-memory-framework/unified-memory-framework/src/pool/pool_disjoint.c:116 (test_memoryPool+0xb7010)
    #3 bucket_create_slab /home/runner/work/unified-memory-framework/unified-memory-framework/src/pool/pool_disjoint.c:345 (test_memoryPool+0xb8a5d)
    #4 bucket_get_avail_slab /home/runner/work/unified-memory-framework/unified-memory-framework/src/pool/pool_disjoint.c:368 (test_memoryPool+0xb8ca6)
    #5 bucket_get_free_chunk /home/runner/work/unified-memory-framework/unified-memory-framework/src/pool/pool_disjoint.c:321 (test_memoryPool+0xb85bf)
    #6 disjoint_pool_aligned_malloc /home/runner/work/unified-memory-framework/unified-memory-framework/src/pool/pool_disjoint.c:763 (test_memoryPool+0xba644)
    #7 umfPoolAlignedMalloc /home/runner/work/unified-memory-framework/unified-memory-framework/src/memory_pool.c:195 (test_memoryPool+0xac901)
    #8 pow2AlignedAllocHelper(umf_memory_pool_t*) /home/runner/work/unified-memory-framework/unified-memory-framework/test/poolFixtures.hpp:216 (test_memoryPool+0x1abf0)
    #9 operator() /home/runner/work/unified-memory-framework/unified-memory-framework/test/poolFixtures.hpp:299 (test_memoryPool+0x1b916)
    #10 __invoke_impl<void, umfPoolTest_multiThreadedpow2AlignedAlloc_Test::TestBody()::<lambda(umf_memory_pool_handle_t)>, umf_memory_pool_t*> /usr/include/c++/11/bits/invoke.h:61 (test_memoryPool+0x35b82)
    #11 __invoke<umfPoolTest_multiThreadedpow2AlignedAlloc_Test::TestBody()::<lambda(umf_memory_pool_handle_t)>, umf_memory_pool_t*> /usr/include/c++/11/bits/invoke.h:96 (test_memoryPool+0x35555)
    #12 _M_invoke<0, 1> /usr/include/c++/11/bits/std_thread.h:259 (test_memoryPool+0x34e38)
    #13 operator() /usr/include/c++/11/bits/std_thread.h:266 (test_memoryPool+0x34ade)
    #14 _M_run /usr/include/c++/11/bits/std_thread.h:211 (test_memoryPool+0x348c8)
    #15 <null> <null> (libstdc++.so.6+0xdc252)

  Previous read of size 8 at 0x7f5ae5e5c6e8 by thread T16:
    #0 slab_get_end /home/runner/work/unified-memory-framework/unified-memory-framework/src/pool/pool_disjoint.c:179 (test_memoryPool+0xb744f)
    #1 disjoint_pool_free /home/runner/work/unified-memory-framework/unified-memory-framework/src/pool/pool_disjoint.c:843 (test_memoryPool+0xbac10)
    #2 umfPoolFree /home/runner/work/unified-memory-framework/unified-memory-framework/src/memory_pool.c:215 (test_memoryPool+0xacba9)
    #3 pow2AlignedAllocHelper(umf_memory_pool_t*) /home/runner/work/unified-memory-framework/unified-memory-framework/test/poolFixtures.hpp:224 (test_memoryPool+0x1aef2)
    #4 operator() /home/runner/work/unified-memory-framework/unified-memory-framework/test/poolFixtures.hpp:299 (test_memoryPool+0x1b916)
    #5 __invoke_impl<void, umfPoolTest_multiThreadedpow2AlignedAlloc_Test::TestBody()::<lambda(umf_memory_pool_handle_t)>, umf_memory_pool_t*> /usr/include/c++/11/bits/invoke.h:61 (test_memoryPool+0x35b82)
    #6 __invoke<umfPoolTest_multiThreadedpow2AlignedAlloc_Test::TestBody()::<lambda(umf_memory_pool_handle_t)>, umf_memory_pool_t*> /usr/include/c++/11/bits/invoke.h:96 (test_memoryPool+0x35555)
    #7 _M_invoke<0, 1> /usr/include/c++/11/bits/std_thread.h:259 (test_memoryPool+0x34e38)
    #8 operator() /usr/include/c++/11/bits/std_thread.h:266 (test_memoryPool+0x34ade)
    #9 _M_run /usr/include/c++/11/bits/std_thread.h:211 (test_memoryPool+0x348c8)
    #10 <null> <null> (libstdc++.so.6+0xdc252)

Description

Checklist

• Code compiles without errors locally
• All tests pass locally
• CI workflows execute properly