Update AZP to support stable-2.15 branch

- Fixes #444

Signed-off-by: Hideki Saito <saito@fgrep.org>

.azure-pipelines/azure-pipelines.yml

@@ -61,6 +61,24 @@ stages:
               test: ubuntu2004
             - name: Ubuntu 22.04
               test: ubuntu2204
+  - stage: Docker_2_15
+    displayName: Docker 2.15
+    dependsOn: []
+    jobs:
+      - template: templates/matrix.yml
+        parameters:
+          testFormat: 2.15/linux/{0}/1
+          targets:
+            - name: CentOS 7
+              test: centos7
+            - name: Fedora 37
+              test: fedora37
+            - name: openSUSE 15 py3
+              test: opensuse15
+            - name: Ubuntu 20.04
+              test: ubuntu2004
+            - name: Ubuntu 22.04
+              test: ubuntu2204
   - stage: Docker_2_14
     displayName: Docker 2.14
     dependsOn: []
@@ -203,6 +221,26 @@ stages:
               test: freebsd/12.4
             - name: FreeBSD 13.1
               test: freebsd/13.1
+  - stage: Remote_2_15
+    displayName: Remote 2.15
+    dependsOn: []
+    jobs:
+      - template: templates/matrix.yml
+        parameters:
+          testFormat: 2.15/{0}/1
+          targets:
+            - name: MacOS 13.2
+              test: macos/13.2
+            - name: RHEL 7.9
+              test: rhel/7.9
+            - name: RHEL 8.7
+              test: rhel/8.7
+            - name: RHEL 9.1
+              test: rhel/9.1
+            - name: FreeBSD 12.4
+              test: freebsd/12.4
+            - name: FreeBSD 13.1
+              test: freebsd/13.1
   - stage: Remote_2_14
     displayName: Remote 2.14
     dependsOn: []
@@ -321,6 +359,8 @@ stages:
       - Docker_2_13
       - Remote_2_14
       - Docker_2_14
+      - Remote_2_15
+      - Docker_2_15
       - Remote_devel
       - Docker_devel
     jobs: