CI: bench: default to bash

Author: Anton-Latukha

.github/workflows/bench.yml

@@ -1,5 +1,9 @@
 name: Benchmark
 
+defaults:
+  run:
+    shell: bash
+
 # See: https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#concurrency.
 concurrency:
   group: ${{ github.head_ref }}-${{ github.workflow }}
@@ -89,17 +93,14 @@ jobs:
     - run: cabal configure --enable-benchmarks --max-backjumps 12000
 
     - name: Build
-      shell: bash
       run: cabal build ghcide:benchHist
 
     - name: Bench init
-      shell: bash
       run: cabal bench ghcide:benchHist  -j --benchmark-options="all-binaries"
 
     # tar is required to preserve file permissions
     # compression speeds up upload/download nicely
     - name: tar workspace
-      shell: bash
       run: tar -czf workspace.tar.gz * .git
 
     - name: tar cabal
@@ -159,11 +160,9 @@ jobs:
         tar xzf cabal.tar.gz --directory ~/.cabal
 
     - name: Bench
-      shell: bash
       run: cabal bench ghcide:benchHist  -j --benchmark-options="${{ matrix.example }}"
 
     - name: Display results
-      shell: bash
       run: |
         column -s, -t < ghcide/bench-results/unprofiled/${{ matrix.example }}/results.csv | tee ghcide/bench-results/unprofiled/${{ matrix.example }}/results.txt