community/firefox-119.0-r0: cannot find llvm-objdump on riscv64

firefox fails to build on arch:riscv64 with:

 1:59.41 checking for llvm_profdata... not found
 1:59.98 checking for llvm-objdump... not found
 1:59.99 DEBUG: llvm_objdump: Looking for llvm-objdump
 1:59.99 ERROR: Cannot find llvm-objdump
 Config object not found by mach.
*** Fix above errors and then restart with "./mach build"

See:

• https://build.alpinelinux.org/buildlogs//build-edge-riscv64/community/firefox/firefox-119.0-r0.log