Remove signing script.

The script was not removed when cleaning up the old functionality.

Change-Id: I20cfb323b3d6d05f2f6d268e05725680ecfef357
Reviewed-on: https://flutter-review.googlesource.com/c/recipes/+/52601
Reviewed-by: Xilai Zhang <xilaizhang@google.com>
Commit-Queue: Godofredo Contreras <godofredoc@google.com>
diff --git a/recipes/engine_v2/signer.resources/import_certificate.sh b/recipes/engine_v2/signer.resources/import_certificate.sh
deleted file mode 100644
index f4151e1..0000000
--- a/recipes/engine_v2/signer.resources/import_certificate.sh
+++ /dev/null
@@ -1,10 +0,0 @@
-#!/bin/bash
-
-# Helper script to import a flutter p12 identity.
-# Note: do not enable -x to display expanded values of the variables, as this will leak the passwords.
-set -e
-
-RAW_PASSWORD=$(cat $FLUTTER_P12_PASSWORD)
-# Only filepath with a .p12 suffix will be recognized
-mv $FLUTTER_P12 $P12_SUFFIX_FILEPATH
-/usr/bin/security import $P12_SUFFIX_FILEPATH -k build.keychain -P $RAW_PASSWORD -T $CODESIGN_PATH -T /usr/bin/codesign
\ No newline at end of file