fix: pin DockerInstaller to v26.1.4 for API compatibility (#105)

The default DockerInstaller@0 version (17.09.0-ce) uses Docker API v1.32,
which is rejected by newer daemons requiring minimum API v1.40.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: jamesadevine

templates/base.yml

@@ -171,6 +171,8 @@ jobs:
 
       - task: DockerInstaller@0
         displayName: "Install Docker"
+        inputs:
+          dockerVersion: 26.1.4
 
       - bash: |
           AWF_VERSION="{{ firewall_version }}"
@@ -332,6 +334,8 @@ jobs:
 
       - task: DockerInstaller@0
         displayName: "Install Docker"
+        inputs:
+          dockerVersion: 26.1.4
 
       - bash: |
           AWF_VERSION="{{ firewall_version }}"