Numpy 2.0: `np.string_` -> `np.bytes_`#78

ax3l merged 1 commit intoopenPMD:2.0.XopenPMD/openPMD-validator:2.0.Xfrom

ax3l:fix-np-2.0-fixed-size-str-2.0.Xax3l/openPMD-validator:fix-np-2.0-fixed-size-str-2.0.XCopy head branch name to clipboard