ci(vortex-row): fold row_encode benchmarks into CodSpeed shard 8

Run the vortex-row row_encode benchmarks as part of the existing 'Storage formats'
shard rather than adding a dedicated ninth shard.

Signed-off-by: Joe Isaacs <joe.isaacs@live.co.uk>

Author: joseph-isaacs

.github/workflows/codspeed.yml

@@ -34,8 +34,7 @@ jobs:
           - { shard: 5, name: "Encodings 2", packages: "vortex-decimal-byte-parts vortex-fastlanes vortex-fsst", features: "--features _test-harness" }
           - { shard: 6, name: "Encodings 3", packages: "vortex-pco vortex-runend vortex-sequence" }
           - { shard: 7, name: "Encodings 4", packages: "vortex-sparse vortex-zigzag vortex-zstd" }
-          - { shard: 8, name: "Storage formats", packages: "vortex-flatbuffers vortex-proto vortex-btrblocks" }
-          - { shard: 9, name: "Row encoding", packages: "vortex-row" }
+          - { shard: 8, name: "Storage formats & row encoding", packages: "vortex-flatbuffers vortex-proto vortex-btrblocks vortex-row" }
     name: "Benchmark with Codspeed (Shard #${{ matrix.shard }})"
     timeout-minutes: 30
     runs-on: >-