backgrounds,backwards_ecal: pin packages to compatible versions

benchmarks/backgrounds/requirements.txt

-awkward >= 2.4.0
-dask >= 2023
-dask_awkward
-dask_histogram
-distributed >= 2023
+awkward ~= 2.7.2
+dask ~= 2024.12.1
+dask_awkward ~= 2024.12.2
+dask_histogram ~= 2024.12.1
+distributed ~= 2024.12.1
 pyhepmc
-uproot >= 5.2.0
+uproot ~= 5.5.1

benchmarks/backwards_ecal/requirements.txt

-awkward >= 2.4.0
-boost_histogram
-dask >= 2024
-dask_awkward >= 2024
-dask_histogram
-distributed >= 2024
-uproot >= 5.2.0
-vector
+awkward ~= 2.7.2
+dask ~= 2024.12.1
+dask_awkward ~= 2024.12.2
+dask_histogram ~= 2024.12.1
+distributed ~= 2024.12.1
+pyhepmc
+uproot ~= 5.5.1
+vector ~= 1.5.2