docs: rename ELECTRON_CACHE env variable to electron_config_cache (#21313)

docs/tutorial/installation.md

@@ -82,7 +82,7 @@ with the network at all.
 On environments that have been using older versions of Electron, you might find the
 cache also in `~/.electron`.
 
-You can also override the local cache location by providing a `ELECTRON_CACHE`
+You can also override the local cache location by providing a `electron_config_cache`
 environment variable.
 
 The cache contains the version's official zip file as well as a checksum, stored as