[Java] Upgrade to flatc version 23.5.26

[danepitkin]

Describe the enhancement requested

flatc v23.5.26 is the same version now used in C++. See #38650 (comment)

Component(s)

Java

[lidavidm]

Tagging as breaking change since an upstream Flatbuffers change means that a method that was previously generated in Feature.java is no longer present. (It's doubtful anyone actually uses it, but just in case.)