CI: Emacs installed with ancient Ubuntu is too old

.github/workflows/test-pgv12.yml

@@ -28,9 +28,9 @@ jobs:
 
     steps:
       - name: Install Emacs
-        run: |
-          sudo apt-get update
-          sudo apt-get install emacs
+        uses: purcell/setup-emacs@master
+        with:
+           version: 29.1
 
       - name: Check out repository code
         uses: actions/checkout@v4

.github/workflows/test-pgv15.yml

@@ -29,10 +29,12 @@ jobs:
           - /var/run/postgresql:/var/run/postgresql
 
     steps:
+      # The version of Emacs available in the ancient Ubuntu distribution used by GitHub
+      # actions is too old.
       - name: Install Emacs
-        run: |
-          sudo apt-get update
-          sudo apt-get install emacs
+        uses: purcell/setup-emacs@master
+        with:
+           version: 29.2
 
       - name: Check out repository code
         uses: actions/checkout@v4

.github/workflows/test-pgv16.yml

@@ -29,10 +29,12 @@ jobs:
           - /var/run/postgresql:/var/run/postgresql
 
     steps:
+      # The version of Emacs available in the ancient Ubuntu distribution used by GitHub
+      # actions is too old.
       - name: Install Emacs
-        run: |
-          sudo apt-get update
-          sudo apt-get install emacs
+        uses: purcell/setup-emacs@master
+        with:
+           version: 29.2
 
       - name: Check out repository code
         uses: actions/checkout@v4

README.md

@@ -59,8 +59,9 @@ Tested with Emacs versions 29.1, 28.2, 27.2 and 26.3. Emacs versions older than
 against a recent PostgreSQL version (whose default configuration requires SCRAM-SHA-256
 authentication), because they don't include the GnuTLS support which we use to calculate HMACs. They
 may however work against a database set up to allow unauthenticated local connections. Emacs
-versions older than 28.1 will not be able to use the extended query protocol (prepared statements),
-because they don't have the necessary bindat functionality.
+versions older than 28.1 (from April 2022) will not be able to use the extended query protocol
+(prepared statements), because they don't have the necessary bindat functionality. It should however
+be easy to update the installed version of bindat.el for these older versions.
 
 You may be interested in an alternative library [emacs-libpq](https://github.com/anse1/emacs-libpq)
 that enables access to PostgreSQL from Emacs by binding to the libpq library.