Hack to work around broken POSTGRES_DISTRIB_DIR path since v15 support

I just want to run the one benchmark manually

.github/workflows/benchmarking.yml

@@ -140,7 +140,7 @@ jobs:
     env:
       TEST_PG_BENCH_DURATIONS_MATRIX: "60m"
       TEST_PG_BENCH_SCALES_MATRIX: "10gb"
-      POSTGRES_DISTRIB_DIR: /usr
+      POSTGRES_DISTRIB_DIR: /tmp/pg_install
       TEST_OUTPUT: /tmp/test_output
       BUILD_TYPE: remote
       SAVE_PERF_REPORT: ${{ github.event.inputs.save_perf_report || ( github.ref == 'refs/heads/main' ) }}
@@ -151,7 +151,7 @@ jobs:
         # neon-captest-new: Run pgbench in a freshly created project
         # neon-captest-reuse: Same, but reusing existing project
         # neon-captest-prefetch: Same, with prefetching enabled (new project)
-        platform: [ neon-captest-new, neon-captest-reuse, neon-captest-prefetch, rds-aurora ]
+        platform: [ neon-captest-reuse ]
 
     runs-on: dev
     container:
@@ -201,6 +201,13 @@ jobs:
       env:
         PLATFORM: ${{ matrix.platform }}
 
+    - name: Hack psql path
+      run: |
+        mkdir /tmp/pg_install
+        ln -s /usr/ /tmp/pg_install/v14
+      env:
+        BENCHMARK_CONNSTR: ${{ steps.set-up-connstr.outputs.connstr }}
+
     - name: Set database options
       if: matrix.platform == 'neon-captest-prefetch'
       run: |