Remove submodules

The Zephyr/Pigweed developers want to use Zephyr's "west" tool which
does many things but for our purposes is like the Android Repo Tool.
Pigweed has no intention of supporting west but can mimic it with an
Android Repo Tool project with the same directory structure. Removing
the submodules because, for Pigweed, these will not be used.

Change-Id: I1171ffc6d8a517449c78fb115fac4c8485308799
Bug: b/267213895
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/zephyr-integration/+/139270
Reviewed-by: Erik Gilling <konkers@google.com>
Commit-Queue: Rob Mohr <mohrr@google.com>

.gitmodules

diff --git a/.gitmodules b/.gitmodules
index d18bef0..e69de29 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,8 +0,0 @@
-[submodule "pigweed"]
-	path = pigweed
-	url = ../pigweed
-	branch = main
-[submodule "zephyr"]
-	path = zephyr
-	url = ../../third_party/github/zephyrproject-rtos/zephyr
-	branch = main

pigweed

diff --git a/pigweed b/pigweed
deleted file mode 160000
index 78ad640..0000000
--- a/pigweed
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 78ad6403cc6760021e89e8bb9b6c27c54af29f33

zephyr

diff --git a/zephyr b/zephyr
deleted file mode 160000
index 10130d8..0000000
--- a/zephyr
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 10130d8e6de8c3889f42d498d3de6115db8f2d35