Do not run regress workflows on benign changes

If only documentation is changed, the full regression check workflow
will still be executed, so this commit will instead skip running the
regression workflows if there are only changes to files that will not
affect the success of the workflow.

.github/workflows/linux-32bit-build-and-test.yaml

@@ -4,7 +4,19 @@ on:
     branches:
       - main
       - prerelease_test
+    paths-ignore:
+      - '**.md'
+      - LICENSE
+      - NOTICE
+      - 'bootstrap*'
+      - '.??*'
   pull_request:
+    paths-ignore:
+      - '**.md'
+      - LICENSE
+      - NOTICE
+      - 'bootstrap*'
+      - '.??*'
 jobs:
   config:
     runs-on: ubuntu-latest

.github/workflows/linux-build-and-test.yaml

@@ -11,7 +11,19 @@ on:
     branches:
       - main
       - prerelease_test
+    paths-ignore:
+      - '**.md'
+      - LICENSE
+      - NOTICE
+      - 'bootstrap*'
+      - '.??*'
   pull_request:
+    paths-ignore:
+      - '**.md'
+      - LICENSE
+      - NOTICE
+      - 'bootstrap*'
+      - '.??*'
 jobs:
   matrixbuilder:
     runs-on: ubuntu-latest

.github/workflows/required-workflows.yaml

@@ -0,0 +1,32 @@
+# If a required workflow is ignored, the PR will not be accepted, so
+# we create an alternative workflow that will succeed in the cases
+# where a workflow does not run.
+name: Required workflows that are ignored
+on:
+  push:
+    branches:
+      - prerelease_test
+    paths:
+      - '**.md'
+      - LICENSE
+      - NOTICE
+      - 'bootstrap*'
+      - '.??*'
+  pull_request:
+    paths:
+      - '**.md'
+      - LICENSE
+      - NOTICE
+      - 'bootstrap*'
+      - '.??*'
+jobs:
+  regress_linux_32bit:
+    runs-on: ubuntu-latest
+    steps:
+      - run: |
+          echo "No build required"
+  regress:
+    runs-on: ubuntu-latest
+    steps:
+      - run: |
+          echo "No build required"

.github/workflows/shellcheck.yaml

@@ -6,6 +6,8 @@ on:
     branches:
       - main
       - prerelease_test
+    paths:
+      - '**.sh'
 jobs:
   shellcheck:
     name: Shellcheck