Revert Revert "[Doc] Add Algolia search to docs" (ray-project#47487)

Redo https://github.com/ray-project/ray/pull/47483/files. The previous
PR was based on a too old base so it gets merged successfully without
re-compiling the dependencies

Also allow the dry-run of generating build cache to run on premerge, to
block changes that can break it.

Test:
- CI

Signed-off-by: can <[email protected]>
Signed-off-by: ujjawal-khare <[email protected]>

doc/requirements-doc.txt

@@ -7,7 +7,7 @@ setuptools>=70.0.0
 Pygments==2.16.1
 
 # Sphinx
-sphinx==7.1.2
+sphinx==7.3.7
 sphinx-click==5.1.0
 sphinx-copybutton==0.5.2
 sphinxemoji==0.2.0
@@ -20,6 +20,7 @@ sphinx-autobuild==2024.4.16
 pydata-sphinx-theme==0.14.1
 autodoc_pydantic==2.2.0
 appnope
+sphinx-docsearch==0.0.7
 
 pydantic!=2.0.*,!=2.1.*,!=2.2.*,!=2.3.*,!=2.4.*,<3
 

doc/source/conf.py

@@ -70,8 +70,14 @@
     "sphinx_remove_toctrees",
     "sphinx_design",
     "sphinx.ext.intersphinx",
+    "sphinx_docsearch",
 ]
 
+# Configuration for algolia
+docsearch_app_id = "LBHF0PABBL"
+docsearch_api_key = "6c42f30d9669d8e42f6fc92f44028596"
+docsearch_index_name = "docs-ray"
+
 remove_from_toctrees = [
     "cluster/running-applications/job-submission/doc/*",
     "ray-observability/reference/doc/*",