update cache helper to skip to a "neutral" folder to check remote from

works around an issue where .git can get confused when checking a remote for its hash, and where the below command fails on corrupted .git folders.  This happens to me locally when building lambda_container, as some .git folder abomination gets put into the context when building. should probably review what's in our .dockerignore's as well.

```
git ls-remote https://github.com/rive-app/skia rive

fatal: not a git repository: /app/submodules/rive-recorder/submodules/rive-cpp/../../../../.git/modules/submodules/rive-recorder/modules/submodules/rive-cpp
```

Diffs=
e2d64593f update cache helper to skip to a "neutral" folder to check remote from

.rive_head

diff --git a/.rive_head b/.rive_head
index fc8031f..c218643 100644
--- a/.rive_head
+++ b/.rive_head
@@ -1 +1 @@
-7f7d459dc0f9cc0daf6010b646ba344c8a9431ef
+e2d64593f3e48beeb08f27aadb20d261227a8ccd

skia/dependencies/cache_helper.sh

diff --git a/skia/dependencies/cache_helper.sh b/skia/dependencies/cache_helper.sh
index b4abf77..6940bfb 100755
--- a/skia/dependencies/cache_helper.sh
+++ b/skia/dependencies/cache_helper.sh
@@ -20,11 +20,15 @@
     exit 1
 fi
 
-# determeined envs
+# computed environment variables
 SKIA_DEPENDENCIES_DIR="$RIVE_RUNTIME_DIR/skia/dependencies"
 SKIA_DIR="$SKIA_DEPENDENCIES_DIR/$SKIA_DIR_NAME"
 
+# gotta switch into a non .git folder to check the remote repo's hash
+# this avoid issues with corrupted git repos throwing irrelevant errors
+pushd ~
 SKIA_COMMIT_HASH="$(git ls-remote $SKIA_REPO $SKIA_BRANCH | awk '{print $1}')"
+popd 
 
 ARCHIVE_CONTENTS_PATH="$SKIA_DIR/$ARCHIVE_CONTENTS_NAME"
 echo $ARCHIVE_CONTENTS_PATH