ci: drop unneeded npm@latest update step

The release workflow's first action installed npm@latest before running
semantic-release. The current latest npm (11.x) ships broken with a
MODULE_NOT_FOUND for promise-retry, which fails the entire release run.
Node 22's bundled npm (10.x) works fine with semantic-release, so this
upgrade step is unnecessary churn that exposes us to upstream npm bugs.

Removing it unblocks the SIT-163 release.

Author: onamfc

.github/workflows/release.yml

@@ -38,9 +38,6 @@ jobs:
           node-version: '22'
           cache: 'npm'
 
-      - name: Update npm to latest
-        run: npm install -g npm@latest
-
       - name: Install dependencies
         run: npm ci