https://bugs.ruby-lang.org/issues/21785#note-10
> It is too late to introduce it in Ruby 4.0, let's aim for 4.1.
This reverts commits:
* d0b72429a93e54f1f956b4aedfc25c57dc7001aa
Add support for signed and unsigned LEB128 to pack/unpack.
* 68a900e30b4ca1537d7975c3a619fd94fca7b084
add news for pack / unpack directives
This commit adds a new pack format command `R` and `r` for unsigned and
signed LEB128 encoding. The "r" mnemonic is because this is a
"vaRiable" length encoding scheme.
LEB128 is used in various formats including DWARF, WebAssembly, MQTT,
and Protobuf.
[Feature #21785]
