These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.87 s (backtrack: 0/20).

[ebuild     UD ] sys-libs/gdbm-1.25:0/6::gentoo [1.26:0/6::gentoo] USE="nls readline -berkdb* -static-libs -test -verify-sig" 1196 KiB

Total: 1 package (1 downgrade), Size of downloads: 1196 KiB

!!! Multiple package instances within a single package slot have been pulled
!!! into the dependency graph, resulting in a slot conflict:

sys-libs/gdbm:0

  (sys-libs/gdbm-1.25:0/6::gentoo, ebuild scheduled for merge) USE="nls readline -berkdb -static-libs -test -verify-sig" pulled in by
    =sys-libs/gdbm-1.25 (Argument)

  (sys-libs/gdbm-1.26:0/6::gentoo, installed) USE="berkdb nls readline -static-libs -test -verify-sig" pulled in by
    sys-libs/gdbm:0/6=[berkdb] required by (dev-lang/python-3.13.12:3.13/3.13::gentoo, installed) USE="ensurepip gdbm ncurses pgo readline sqlite ssl -bluetooth -debug -examples (-jit) -libedit -test -tk -valgrind -verify-sig" LLVM_SLOT="18"
                       ^^^^^^                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
    sys-libs/gdbm:0/6=[berkdb] required by (dev-lang/python-3.14.3:3.14/3.14::gentoo, installed) USE="ensurepip gdbm ncurses pgo readline sqlite ssl -bluetooth -debug -examples (-jit) -libedit -tail-call-interp -test -tk -valgrind -verify-sig" LLVM_SLOT="19"
                       ^^^^^^                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               


It might be possible to solve this slot collision
by applying all of the following changes:
   - sys-libs/gdbm-1.25 (Change USE: +berkdb)