rolling-release-update.py: Ruff formatting

This was done automatically by ruff format. Default configuration is used.

Important:
is_rebuild variable was never used. Therefore I removed this:
```
if b"Rebuild rocky" in line:
	is_rebuild = True
```

Signed-off-by: Roxana Nicolescu <rnicolescu@ciq.com>

Author: roxanan1996

.pre-commit-config.yaml

@@ -11,6 +11,5 @@ repos:
 
 exclude: |
   (?x)^(
-  rolling-release-update.py |
   run_interdiff.py |
   )$