build failure on Ubuntu21 gcc10.3: drrun has too-recent import: GLOBAL DEFAULT UND stat@GLIBC_2.33

While reproducing DynamoRIO/drmemory#2425 I made an Ubuntu 21.04 VM and it fails to build all of DR:

CMake Error at /home/derek/drmemory/git/src/dynamorio/core/CMake_readelf.cmake:146 (message):
  *** Error: /home/derek/drmemory/git/build_x64_dbg/dynamorio/bin64/drrun has
  too-recent import: GLOBAL DEFAULT UND stat@GLIBC_2.33 (3)