use dependabot, update CI triggers, fix RTD builds (#5)

* Create dependabot.yml for github actions updates
* Update .readthedocs.yml to fix RTD builds
* don't trigger build CI twice in a PR

.github/dependabot.yml

@@ -0,0 +1,13 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://docs.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    # Workflow files stored in the
+    # default location of `.github/workflows`
+    directory: "/"
+    schedule:
+      interval: "weekly"

.github/workflows/build.yml

@@ -2,8 +2,9 @@ name: Build CI
 
 on:
   pull_request:
-    types: [opened, reopened]
+    branches: [master]
   push:
+    branches: [master]
 
 jobs:
   build-wheel:

.readthedocs.yml

@@ -1,8 +1,12 @@
 version: 2
 
+build:
+  os: "ubuntu-22.04"
+  tools:
+    python: "3.11"
+
 python:
-  version: 3
   install:
     - requirements: docs/requirements.txt
     - method: pip
-      path: .
+      path: .