cross/musl-*: upgrade to 1.2.5_git20251012

This is an upgrade, despite the pervious version being 1.2.6_git… (it was wrong, see related commit).

• Related: https://gitlab.alpinelinux.org/alpine/aports/-/commit/e4b8c67bb1d2d22e98f0c00b50b7fb0b71eee6c9
• Related: https://gitlab.alpinelinux.org/alpine/aports/-/commit/28eb815e5d8bacf7467aed9db0fc6ac026e97cea