Bump pbr from 5.4.2 to 5.4.3 in /requirements (#5492)

Bumps [pbr](https://docs.openstack.org/pbr/latest/) from 5.4.2 to 5.4.3.

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

requirements/dev.txt

@@ -70,9 +70,9 @@ wcwidth==0.1.7 \
 
 # Required by mock
 funcsigs==1.0.2 --hash=sha256:330cc27ccbf7f1e992e69fef78261dc7c6569012cf397db8d3de0234e6c937ca
-pbr==5.4.2 \
-    --hash=sha256:56e52299170b9492513c64be44736d27a512fa7e606f21942160b68ce510b4bc \
-    --hash=sha256:9b321c204a88d8ab5082699469f52cc94c5da45c51f114113d01b3d993c24cdf
+pbr==5.4.3 \
+    --hash=sha256:b32c8ccaac7b1a20c0ce00ce317642e6cf231cf038f9875e0280e28af5bf7ac9 \
+    --hash=sha256:2c8e420cd4ed4cec4e7999ee47409e876af575d4c35a45840d59e8b5f3155ab8
 
 # Required by flake8
 entrypoints==0.3 --hash=sha256:589f874b313739ad35be6e0cd7efde2a4e9b6fea91edcc34e58ecbb8dbe56d19