Bump ubuntu from `8a37d68` to `dfc1087` in /docker/exodus #2038

Job	Run time
build-deps (gnu, V114, 4.9.2, 4.4.0)	40s
build-deps (clang, V114, 4.9.2, 4.4.0)	40s
build-deps (mpi, V114, 4.9.2, 4.4.0)	57s
Debug serial build	6m 4s
Debug parallel build	6m 40s
Threadsafe ON, No Fortran	4m 16s
Threadsafe ON, Parallel, No Fortran	5m 25s
Sanitize address, no fortran	6m 15s
Sanitize undefined	7m 13s
Sanitize integer	5m 4s
GTest Enabled	6m 25s
No applications, legacy, or fortran	4m 3s
CATALYST2, parallel	9m 6s
KOKKOS, parallel	8m 7s
No deprecated exodus functions	7m 51s
Use modern CMake configure of netCDF and HDF5 packages with GTest	8m 12s
ADIOS2 enabled	11m 57s
FAODEL and METIS enabled	12m 12s
C++20 build serial clang	6m 54s
C++20 build serial gnu	7m 7s
C++20 build parallel	8m 26s
	2h 13m 34s

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