[ci] drop pull_request: paths: constraints (#956)

This is open to much opinion.  I find it a hassle to maintain and also risky.  For example, `tests.yml` uses tox and thus `tox.ini` but as is editing that file wouldn't trigger a run.  Let me know how you feel about this.
diff --git a/.github/workflows/build-and-publish.yml b/.github/workflows/build-and-publish.yml
index 08a6621..f9381cb 100644
--- a/.github/workflows/build-and-publish.yml
+++ b/.github/workflows/build-and-publish.yml
@@ -20,9 +20,8 @@
     branches:
       - master
   pull_request:
-    paths:
-      - ".github/workflows/build-and-publish.yml"
-      - "setup.*"
+    branches:
+      - '**'
 
   workflow_dispatch:
     inputs:
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 83a679b..fbc65a8 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -5,13 +5,8 @@
     branches:
       - master
   pull_request:
-    paths:
-      - ".github/workflows/tests.yml"
-      - "requirements-tests.txt"
-      - "setup.*"
-      - "src/**/*"
-      - "tests/*.py"
-      - "docs/**/*"
+    branches:
+      - '**'
 
 jobs:
   lint: