ci: bump sigstore/cosign-installer from 3.7.0 to 3.8.1

Bumps [sigstore/cosign-installer](https://github.com/sigstore/cosign-installer) from 3.7.0 to 3.8.1.
- [Release notes](https://github.com/sigstore/cosign-installer/releases)
- [Commits](sigstore/cosign-installer@dc72c7d...d7d6bc7)

---
updated-dependencies:
- dependency-name: sigstore/cosign-installer
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/release-draft-binaries.yml

@@ -246,7 +246,7 @@ jobs:
         ls $GITHUB_WORKSPACE
 
     - name: Install Cosign
-      uses: sigstore/cosign-installer@dc72c7d5c4d10cd6bcb8cf6e3fd625a9e5e537da
+      uses: sigstore/cosign-installer@d7d6bc7722e3daa8354c50bcb52f4837da5e9b6a
       with:
         cosign-release: 'v2.0.0'
 
@@ -359,7 +359,7 @@ jobs:
           echo "FILE_NAME=${final_name}.tar.gz" >> $GITHUB_ENV
 
       - name: Install Cosign
-        uses: sigstore/cosign-installer@dc72c7d5c4d10cd6bcb8cf6e3fd625a9e5e537da
+        uses: sigstore/cosign-installer@d7d6bc7722e3daa8354c50bcb52f4837da5e9b6a
         with:
           cosign-release: 'v2.0.0'
 
@@ -424,7 +424,7 @@ jobs:
         run: shasum -a 256 *ockam* > sha256sums.txt
 
       - name: Install Cosign
-        uses: sigstore/cosign-installer@dc72c7d5c4d10cd6bcb8cf6e3fd625a9e5e537da
+        uses: sigstore/cosign-installer@d7d6bc7722e3daa8354c50bcb52f4837da5e9b6a
         with:
           cosign-release: 'v2.0.0'