fix(build): revert Cloud SDK pin for Debian converter

The switch from `google/cloud-sdk:449.0.0-alpine` to
`gcr.io/google.com/cloudsdktool/google-cloud-cli:alpine` was not a
drop-in replacement:

This moved from Alpine 3.18.4 to 3.20.2 and 3.20.2 is more intolerant of
the `pip install poetry==1.8.3` being performed:

```
error: externally-managed-environment
```

vulnfeeds/tools/debian/Dockerfile

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-FROM gcr.io/google.com/cloudsdktool/google-cloud-cli:alpine@sha256:d5da0344b23d03a6f2728657732c7a60300a91acaad9b8076c6fd30b1dfe1ff4
+FROM google/cloud-sdk:449.0.0-alpine
 
 # Keep the virtualenv directly in the project directory. This isn't strictly neccesary for
 # this project as it runs on kubernetes, but it keeps it consistent with other cloud run images