scripts/release: add missing build to towncrier call

Probably a new thing, but without it it just succeeds without doing
anything.

Author: bluetech

scripts/release.py

@@ -121,7 +121,7 @@ def pre_release(
 
 def changelog(version: str, write_out: bool = False) -> None:
     addopts = [] if write_out else ["--draft"]
-    check_call(["towncrier", "--yes", "--version", version, *addopts])
+    check_call(["towncrier", "build", "--yes", "--version", version, *addopts])
 
 
 def main() -> None: