Docs: remove blank line between supported-platform footnotes

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Author: redsun82

docs/codeql/reusables/supported-platforms.rst

@@ -19,5 +19,4 @@
 .. container:: footnote-group
 
     .. [1] Support for Linux on arm64 is currently in beta.
-
     .. [2] On Apple Silicon, building your code during analysis requires Rosetta 2; analyzing an interpreted language or using build mode ``none`` runs natively.