s2 1.1.2

• Fixed test for as.data.frame() for s2_cell() to comply with new wk
  version and the latest release of R (#207).
• Fix unary union of an empty multipolygon (#208).
• Added #include <cstdint> to an Abseil header to fix compilation with
  gcc13 (#209, #210).
• Update internal Abseil to 20220623.1 LTS (#213).