docs: fix typos and duplicated words across documentation

docs: fix typos and duplicated words across documentation

Fix the following typos and duplicated words:

- admin-guide/pm/intel-speed-select.rst: "weather" -> "whether"
- core-api/real-time/differences.rst: "the the" -> "the"
- admin-guide/bcache.rst: "to to" -> "to"

Signed-off-by: Manuel Cortez <mdjesuscv@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20260406030323.1196-1-mdjesuscv@gmail.com>