ci: rename publish env from public-sdk to publish (#551)

Aligns the python publish workflow with the env name used by all other
workflows. The public-sdk environment no longer exists on the repo
(removed when renaming to publish), so the publish workflow currently
references a non-existent environment.

Author: Nelson-PROIA

.github/workflows/sdk_publish_mistralai_sdk.yaml

@@ -23,7 +23,7 @@ jobs:
       (github.event_name == 'workflow_dispatch' && github.event.inputs.confirm_publish == 'publish')
     runs-on: ubuntu-24.04
     environment:
-      name: public-sdk
+      name: publish
     steps:
       - name: Checkout repository
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4