doc: update toolchain for official releases

RHEL 8 machines now use clang 20.1.

Signed-off-by: Richard Lau <richard.lau@ibm.com>

Author: richardlau

BUILDING.md

@@ -175,10 +175,10 @@ Binaries at <https://nodejs.org/download/release/> are produced on:
 | aix-ppc64               | AIX 7.2 TL04 on PPC64BE with GCC 12[^5]                       |
 | darwin-x64              | macOS 15, Xcode 16 with -mmacosx-version-min=13.5             |
 | darwin-arm64 (and .pkg) | macOS 15 (arm64), Xcode 16 with -mmacosx-version-min=13.5     |
-| linux-arm64             | RHEL 8 with Clang 19.1 and gcc-toolset-14-libatomic-devel[^6] |
-| linux-ppc64le           | RHEL 8 with Clang 19.1 and gcc-toolset-14-libatomic-devel[^6] |
-| linux-s390x             | RHEL 8 with Clang 19.1 and gcc-toolset-14-libatomic-devel[^6] |
-| linux-x64               | RHEL 8 with Clang 19.1 and gcc-toolset-14-libatomic-devel[^6] |
+| linux-arm64             | RHEL 8 with Clang 20.1 and gcc-toolset-14-libatomic-devel[^6] |
+| linux-ppc64le           | RHEL 8 with Clang 20.1 and gcc-toolset-14-libatomic-devel[^6] |
+| linux-s390x             | RHEL 8 with Clang 20.1 and gcc-toolset-14-libatomic-devel[^6] |
+| linux-x64               | RHEL 8 with Clang 20.1 and gcc-toolset-14-libatomic-devel[^6] |
 | win-arm64               | Windows Server 2022 (x64) with Visual Studio 2022             |
 | win-x64                 | Windows Server 2022 (x64) with Visual Studio 2022             |