guix: bump time-machine to efc26826400762207cde9f23802cfe75a737963c

Needed for 30210. This doesn't switch runtimes, because upstream is
still configured to use the old runtime. See:
https://git.savannah.gnu.org/cgit/guix.git/commit/?id=17188be0f723e00377b21b767f5447d7938a116e.

git-mimimal 2.45.1 -> 2.45.2
Kernel Headers 6.1.92 -> 6.1.100
LLVM 18.1.6 -> 18.1.8
mingw-w64 11.0.1 -> 12.0.0
NSIS 3.09 -> 3.10
patch 2.7.6 -> 2.7.6-0.f144b35

contrib/devtools/symbol-check.py

@@ -245,7 +245,7 @@ def check_MACHO_sdk(binary) -> bool:
     return False
 
 def check_MACHO_lld(binary) -> bool:
-    if binary.build_version.tools[0].version == [18, 1, 6]:
+    if binary.build_version.tools[0].version == [18, 1, 8]:
         return True
     return False
 

contrib/guix/libexec/prelude.bash

@@ -51,7 +51,7 @@ fi
 time-machine() {
     # shellcheck disable=SC2086
     guix time-machine --url=https://git.savannah.gnu.org/git/guix.git \
-                      --commit=f0bb724211872cd6158fce6162e0b8c73efed126 \
+                      --commit=efc26826400762207cde9f23802cfe75a737963c \
                       --cores="$JOBS" \
                       --keep-failed \
                       --fallback \