Update sigstore/cosign-installer action to v4 (#119)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/publish-release-element-module.yml

@@ -55,7 +55,7 @@ jobs:
 
             - name: Install Cosign
               if: github.event_name != 'pull_request'
-              uses: sigstore/cosign-installer@59acb6260d9c0ba8f4a2f9d9b48431a222b68e20 # @v3.5.0
+              uses: sigstore/cosign-installer@faadad0cce49287aee09b3a48701e75088a2c6ad # v4.0.0
 
             - name: Set up Docker Buildx
               uses: docker/setup-buildx-action@e468171a9de216ec08956ac3ada2f0791b6bd435 # v3

.github/workflows/publish-release-synapse-module.yml

@@ -53,7 +53,7 @@ jobs:
                   password: ${{ secrets.GITHUB_TOKEN }}
 
             - name: Install Cosign
-              uses: sigstore/cosign-installer@59acb6260d9c0ba8f4a2f9d9b48431a222b68e20 # @v3.5.0
+              uses: sigstore/cosign-installer@faadad0cce49287aee09b3a48701e75088a2c6ad # v4.0.0
 
             - name: Set up Docker Buildx
               uses: docker/setup-buildx-action@e468171a9de216ec08956ac3ada2f0791b6bd435 # v3