[CI] Conform to re2 regexes in branch config

Zuul has deprecated Perl-style syntax; and we're
getting warnings posted against the manifests:

 The RE2 syntax error is: invalid perl operator: (?!

Change-Id: I498573532fd701b47684a54bda9b54b86836afdc
Signed-off-by: Goutham Pacha Ravi <gouthampravi@gmail.com>

zuul.d/manila-tempest-jobs.yaml

@@ -162,7 +162,9 @@
     name: manila-tempest-plugin-zfsonlinux
     description: Test ZFSOnLinux multibackend (DHSS=False) with postgresql db
     parent: manila-tempest-plugin-zfsonlinux-base
-    branches: &ubuntu_jammy_test_image_branches ^(?!stable/(yoga|xena|wallaby|victoria|ussuri)).*$
+    branches: &ubuntu_jammy_test_image_branches
+      regex: ^stable/(yoga|xena|wallaby|victoria|ussuri)$
+      negate: true
 
 - job:
     name: manila-tempest-plugin-lvm-base
@@ -237,7 +239,9 @@
     name: manila-tempest-plugin-lvm
     description: |
       Test LVM multibackend (DHSS=False) in a IPv4 environment.
-    branches: ^(?!stable/(2023.1|zed|yoga|xena|wallaby|victoria|ussuri)).*$
+    branches:
+      regex: ^stable/(2023.1|zed|yoga|xena|wallaby|victoria|ussuri)$
+      negate: true
     parent: manila-tempest-plugin-lvm-base
     vars:
       devstack_localrc:
@@ -730,7 +734,9 @@
 - job:
     name: manila-tempest-plugin-lvm-fips
     parent: manila-tempest-plugin-lvm-fips-base
-    branches: ^(?!stable/(yoga|xena|wallaby|victoria|ussuri)).*$
+    branches:
+      regex: ^stable/(yoga|xena|wallaby|victoria|ussuri)$
+      negate: true
 
 - project-template:
     name: manila-tempest-plugin-jobs-using-service-image

zuul.d/manila-tempest-stable-jobs.yaml

@@ -7,7 +7,7 @@
       Test the scenario test cases on the generic driver multibackend
       (DHSS=True) with NFS and CIFS
     parent: manila-tempest-plugin-generic-scenario-base
-    branches: &manila_tempest_image_pinned_branches ^(stable/(2023.1|zed|yoga|xena)).*$
+    branches: &manila_tempest_image_pinned_branches ^stable/(2023.1|zed|yoga|xena)$
     vars: &manila_tempest_image_pinned_vars
       devstack_localrc:
         # NOTE(carloss): Pinning manila service image to a Focal version,
@@ -65,7 +65,7 @@
 - job:
     name: manila-tempest-plugin-lvm-fips-stable
     parent: manila-tempest-plugin-lvm-fips-base
-    branches: ^(stable/(yoga|xena)).*$
+    branches: ^stable/(yoga|xena)$
     vars: *manila_tempest_image_pinned_vars
 
 - job: