chore(rtx): add lefthook plugin

[`lefthook`][0] is a githook manager for any project.

[0]: https://github.com/evilmartians/lefthook

Dockerfile

@@ -172,6 +172,7 @@ RUN ${XDG_DATA_HOME}/rtx/bin/rtx plugins install \
     erlang \
     helm \
     kubectl \
+    lefthook \
     poetry \
     terraform
 

config/rtx/config.toml

@@ -5,6 +5,7 @@ erlang = "26.1.2"
 go = "1.21.3"
 helm = "3.13.1"
 kubectl = "1.27.7"
+lefthook = "1.5.2"
 node = "21.1.0"
 poetry = "1.6.1"
 python = "3.12.0"