remove debug-logging default from tools profile

`debug-logging` conflicts with `download-rustc` option, and doesn't really
make sense to enable it for a profile that is used for tool development.

Signed-off-by: onur-ozkan <work@onurozkan.dev>

src/bootstrap/defaults/config.tools.toml

@@ -1,10 +1,6 @@
 # These defaults are meant for contributors to tools which build on the
 # compiler, but do not modify it directly.
 [rust]
-# This enables `RUSTC_LOG=debug`, avoiding confusing situations
-# where adding `debug!()` appears to do nothing.
-# However, it makes running the compiler slightly slower.
-debug-logging = true
 # This greatly increases the speed of rebuilds, especially when there are only minor changes. However, it makes the initial build slightly slower.
 incremental = true
 # Download rustc from CI instead of building it from source.