Revert "unpin llama-index-core"

This reverts commit 66bc9cf292.

requirements/common-constraints.txt

@@ -9,8 +9,6 @@ aiohttp==3.11.18
     #   llama-index-core
 aiosignal==1.3.2
     # via aiohttp
-aiosqlite==0.21.0
-    # via llama-index-core
 altair==5.5.0
     # via streamlit
 annotated-types==0.7.0
@@ -237,8 +235,10 @@ kiwisolver==1.4.8
     # via matplotlib
 litellm==1.70.4
     # via -r requirements/requirements.in
-llama-index-core==0.12.37
-    # via llama-index-embeddings-huggingface
+llama-index-core==0.12.26
+    # via
+    #   -r requirements/requirements-help.in
+    #   llama-index-embeddings-huggingface
 llama-index-embeddings-huggingface==0.5.4
     # via -r requirements/requirements-help.in
 lox==0.13.0
@@ -557,7 +557,6 @@ typer==0.15.4
     # via -r requirements/requirements-dev.in
 typing-extensions==4.13.2
     # via
-    #   aiosqlite
     #   altair
     #   anyio
     #   beautifulsoup4

requirements/requirements-help.in

@@ -8,4 +8,4 @@ llama-index-embeddings-huggingface
 #torch==2.2.2
 
 # Later versions break test_help in GitHub Actions on Windows and Ubuntu
-#llama-index-core==0.12.26
+llama-index-core==0.12.26

requirements/requirements-help.txt

@@ -13,10 +13,6 @@ aiosignal==1.3.2
     # via
     #   -c requirements/common-constraints.txt
     #   aiohttp
-aiosqlite==0.21.0
-    # via
-    #   -c requirements/common-constraints.txt
-    #   llama-index-core
 annotated-types==0.7.0
     # via
     #   -c requirements/common-constraints.txt
@@ -133,9 +129,10 @@ joblib==1.5.1
     #   -c requirements/common-constraints.txt
     #   nltk
     #   scikit-learn
-llama-index-core==0.12.37
+llama-index-core==0.12.26
     # via
     #   -c requirements/common-constraints.txt
+    #   -r requirements/requirements-help.in
     #   llama-index-embeddings-huggingface
 llama-index-embeddings-huggingface==0.5.4
     # via
@@ -294,7 +291,6 @@ transformers==4.52.3
 typing-extensions==4.13.2
     # via
     #   -c requirements/common-constraints.txt
-    #   aiosqlite
     #   anyio
     #   huggingface-hub
     #   llama-index-core