component/depot_tools: check out a fixed revision

This was using master branch and when it got renamed to main this
stopped working and we realized that the revision was not pinned.

component/depot_tools/buildout.cfg

 [buildout]
+extends =
+  ../git/buildout.cfg
 parts =
   depot_tools
 
 [depot_tools]
 recipe = slapos.recipe.build:gitclone
 repository = https://chromium.googlesource.com/chromium/tools/depot_tools.git
-branch = master
+revsion = e023d4482012d89690f6a483e877eceb47c4501e
 git-executable = ${git:location}/bin/git