Disable some workflows on PRs that only change docs (#45)

This is a bit risky and we might want to reenable some of these, but
let's see how this goes. Reasoning for the disabled workflows:

- `main.yaml`: This is independent of docs
- `native-bazel.yaml`: Dev-only workflow and covered by nix workflows.
- `native-cargo.yaml`: Dev-only workflow and covered by nix workflows.
- `sanitizers.yaml`: Independent of the docs.

This change deliberately doesn't touch the Nix workflows as parts of the
development tooling used by doc workflows relies on it.

Author: aaronmondal

.github/workflows/main.yml

@@ -6,6 +6,8 @@ on:
     branches: [ main ]
   pull_request:
     branches: [ main ]
+    paths-ignore:
+      - 'docs/**'
 
 permissions: read-all
 

.github/workflows/native-bazel.yaml

@@ -6,6 +6,8 @@ on:
     branches: [main]
   pull_request:
     branches: [main]
+    paths-ignore:
+      - 'docs/**'
 
 permissions: read-all
 

.github/workflows/native-cargo.yaml

@@ -6,6 +6,8 @@ on:
     branches: [main]
   pull_request:
     branches: [main]
+    paths-ignore:
+      - 'docs/**'
 
 permissions: read-all
 

.github/workflows/sanitizers.yaml

@@ -6,6 +6,8 @@ on:
     branches: [main]
   pull_request:
     branches: [main]
+    paths-ignore:
+      - 'docs/**'
 
 permissions: read-all