Remove flake8-broken-line from requirements

Flake8 plugin removed because of dependency incompatibility. See #704. Once, this gets merged we may consider using it again: wemake-services/flake8-broken-line#280.

requirements/flake8.txt

@@ -1,5 +1,4 @@
 flake8==5.0.4
-flake8-broken-line==0.6.0
 flake8-bugbear==22.10.27
 flake8-builtins==2.0.1
 flake8-comprehensions==3.10.1
@@ -8,3 +7,7 @@ flake8-logging-format==0.9.0
 flake8-mutable==1.2.0
 flake8-print==5.0.0
 flake8-simplify==0.19.3
+
+# removed because of dependency incompatibility. See https://github.com/coders4help/volunteer_planner/pull/704
+# once, this gets merged we may consider using it again: https://github.com/wemake-services/flake8-broken-line/pull/280
+# flake8-broken-line==0.6.0