ci/GCS: install gnupg2

Signed-off-by: Adam Olech <aolech@antmicro.com>

.github/workflows/Automerge.yml

diff --git a/.github/workflows/Automerge.yml b/.github/workflows/Automerge.yml
index 5fd81f5..b16010f 100644
--- a/.github/workflows/Automerge.yml
+++ b/.github/workflows/Automerge.yml
@@ -55,7 +55,7 @@
       - name: '🛠️ Setup Python and gsutil'
         run: |
           apt update -qqy
-          apt install -qqy curl python3
+          apt install -qqy curl python3 gnupg2
           echo "deb [signed-by=/usr/share/keyrings/cloud.google.gpg] https://packages.cloud.google.com/apt cloud-sdk main" | tee -a /etc/apt/sources.list.d/google-cloud-sdk.list
           curl https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key --keyring /usr/share/keyrings/cloud.google.gpg add -
           apt update -qqy