ci(bench): clarify reusable benchmark workflow names

Rename the two vague reusable-workflow display names: "Core benchmarks" ->
"Rust micro-benchmarks" (it runs the random-access and compression micro-
benchmarks) and "SQL-related benchmarks" -> "SQL benchmarks". Display-name-only
changes; callers reference these workflows by path, so nothing else changes.

Signed-off-by: Connor Tsui <connor@spiraldb.com>
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PQg1cgPLKJg4QVJvE2xa3Q

Author: connortsui20

.github/workflows/bench-core.yml

@@ -1,4 +1,4 @@
-name: "Core benchmarks"
+name: Rust micro-benchmarks
 
 # Reusable workflow for the Rust micro-benchmarks (random access, compression). Called by bench.yml
 # (mode=develop) and bench-pr.yml (mode=pr). The matrix is resolved declaratively from

.github/workflows/sql-benchmarks.yml

@@ -1,4 +1,4 @@
-name: "SQL-related benchmarks"
+name: SQL benchmarks
 
 on:
   workflow_call: