pw_toolchain: Add {{frameworks}} to link command
pw_toolchain: Add {{frameworks}} to link command

It turns out that putting frameworks in {{libs}} was deprecated and is
removed as of gn 3028c6a4 ("[apple] Remove support for frameworks in
libs").

Add frameworks to link command so that adding frameworks via configs
works.

Change-Id: I2360b70bb80e46a0aada40302635b85888adb564
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/14602
Reviewed-by: Keir Mierle <69344103cc60b36d6e1fbdc31ce6504b2286c646@google.com>
Commit-Queue: Michael Spang <e1fb1a05abba8fb04acbcbe6d766da7764320db0@google.com>

google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed