chore: fix errors in .github/workflows/rust-release.yml and prep 0.0.2504292006 release (#745)

Apparently I made two key mistakes in
https://github.com/openai/codex/pull/740 (fixed in this PR):

* I forgot to redefine `$dest` in the `Stage Linux-only artifacts` step
* I did not define the `if` check correctly in the `Stage Linux-only
artifacts` step

This fixes both of those issues and bumps the workspace version to
`0.0.2504292006` in preparation for another release attempt.

.github/workflows/rust-release.yml

@@ -106,10 +106,11 @@ jobs:
           cp target/${{ matrix.target }}/release/codex-exec "$dest/codex-exec-${{ matrix.target }}"
           cp target/${{ matrix.target }}/release/codex "$dest/codex-${{ matrix.target }}"
 
-      - if: ${{ matrix.target == 'x86_64-unknown-linux-musl' }} || ${{ matrix.target == 'aarch64-unknown-linux-gnu' }}
+      - if: ${{ matrix.target == 'x86_64-unknown-linux-musl' || matrix.target == 'aarch64-unknown-linux-gnu' }}
         name: Stage Linux-only artifacts
         shell: bash
         run: |
+          dest="dist/${{ matrix.target }}"
           cp target/${{ matrix.target }}/release/codex-linux-sandbox "$dest/codex-linux-sandbox-${{ matrix.target }}"
 
       - name: Compress artifacts