update bash to 5.x for lastpipe support

Author: shinymack

.github/utilities/run_examples.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/opt/homebrew/bin/bash
 
 # Script to run all example notebooks.
 set -euxo pipefail

.github/workflows/periodic_tests.yml

@@ -46,12 +46,17 @@ jobs:
           extra_args: --all-files
 
   run-notebook-examples:
-    runs-on: ubuntu-24.04
+    runs-on: macos-latest
 
     steps:
       - name: Checkout
         uses: actions/checkout@v4
 
+      - name: Install bash 5.x
+        run: |
+          brew install bash
+          /opt/homebrew/bin/bash --version
+          
       - name: Setup Python 3.10
         uses: actions/setup-python@v5
         with:

.github/workflows/pr_examples.yml

@@ -19,12 +19,17 @@ concurrency:
 
 jobs:
   run-notebook-examples:
-    runs-on: ubuntu-24.04
+    runs-on: macos-latest
 
     steps:
       - name: Checkout
         uses: actions/checkout@v4
 
+      - name: Install bash 5.x
+        run: |
+          brew install bash
+          /opt/homebrew/bin/bash --version
+
       - name: Setup Python 3.10
         uses: actions/setup-python@v5
         with: