Support using Python 3.12 with Khoj (#690)

### Why
- Python 3.12 is the default Python on Ubuntu 24.04 LTS, Windows and Mac via Homebrew
- Python 3.12 has a bunch of improvements that can be explored with Khoj (e.g per core GIL for performance)

## Changes
- The latest PyTorch now supports Python 3.12
- RapidOCR for indexing image PDFs doesn't currently support python 3.12.
  But it's an optional dependency, so only install it if python < 3.12

### Testing
- Verified Khoj installs fine on Windows and Mac with Python 3.12
- Verified Khoj chat works fine on Mac, Windows with Python 3.12

Resolves #522

.github/workflows/build_khoj_el.yml

@@ -21,9 +21,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
-    - name: Set up Python 3.9
+    - name: Set up Python 3.11
       uses: actions/setup-python@v1
-      with: { python-version: 3.9 }
+      with: { python-version: 3.11 }
     - name: ⏬️ Install Dependencies
       run: |
         python -m pip install --upgrade pip

.github/workflows/pre-commit.yml

@@ -31,7 +31,7 @@ jobs:
         with:
           fetch-depth: 0
 
-      - name: Set up Python
+      - name: Set up Python 3.11
         uses: actions/setup-python@v4
         with:
           python-version: 3.11

.github/workflows/test.yml

@@ -32,6 +32,7 @@ jobs:
           - '3.9'
           - '3.10'
           - '3.11'
+          - '3.12'
 
     services:
       postgres:

pyproject.toml

@@ -30,6 +30,7 @@ classifiers = [
     "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
     "Topic :: Internet :: WWW/HTTP :: Indexing/Search",
     "Topic :: Scientific/Engineering :: Artificial Intelligence",
     "Topic :: Scientific/Engineering :: Human Machine Interfaces",
@@ -47,12 +48,12 @@ dependencies = [
     "tenacity >= 8.2.2",
     "pillow ~= 9.5.0",
     "pydantic >= 2.0.0",
-    "pyyaml == 6.0",
+    "pyyaml ~= 6.0",
     "rich >= 13.3.1",
     "schedule == 1.1.0",
     "sentence-transformers == 2.5.1",
     "transformers >= 4.28.0",
-    "torch == 2.0.1",
+    "torch == 2.2.2",
     "uvicorn == 0.17.6",
     "aiohttp ~= 3.9.0",
     "langchain <= 0.2.0",
@@ -70,7 +71,7 @@ dependencies = [
     "gunicorn == 21.2.0",
     "lxml == 4.9.3",
     "tzdata == 2023.3",
-    "rapidocr-onnxruntime == 1.3.11",
+    "rapidocr-onnxruntime == 1.3.11; python_version<'3.12'",
     "openai-whisper >= 20231117",
     "django-phonenumber-field == 7.3.0",
     "phonenumbers == 8.13.27",