roll: third_party/pigweed pw_bluetooth_sapphire: Remove uses of EventCallbackVariant

Remove EventCallbackVariant uses in ScoConnectionManager and
BrEdrConnectionManager now that they are only used in conjunction
with EmbossEventCallbacks.

Original-Bug: b/42167863
Test: pw presubmit --step gn_chre_googletest_nanopb_sapphire_build
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/246312
Original-Revision: ef86a47f69065196b3c5ee0a6b2616e4e3bd553a

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: 19e98dd2e2b099..ef86a47f690651
Roll-Count: 1
Roller-URL: https://cr-buildbucket.appspot.com/build/8732429452450805265
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I2528f0ea4fc76c40487f1ed1b2110e476f474e08
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/245868
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 19e98dd..ef86a47 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 19e98dd2e2b099c5e860aea0d948ccf705039929
+Subproject commit ef86a47f69065196b3c5ee0a6b2616e4e3bd553a