Upgrade Aer to 0.14 (#1127)

Also explain what to install to get the notebooks working locally.
Tested on macOS Apple Silicon. The Linux requirements come from CI but
weren't tested locally.

.gitignore

@@ -5,6 +5,7 @@
 .tox/
 docs/.gitkeep
 .envrc
+latex_error.log
 
 .ipynb_checkpoints/
 .DS_Store

README.md

@@ -100,6 +100,8 @@ To execute notebooks in a fixed Python environment, first install `tox` using
 pipx install tox
 ```
 
+You also need to install a few system dependencies: TeX, Poppler, and graphviz. On macOS, you can run `brew install mactex-no-gui poppler graphviz`. On Ubuntu, you can run `apt-get install texlive-pictures texlive-latex-extra poppler-utils graphviz`.
+
 - To execute all notebooks, run tox.
   ```sh
   tox

scripts/nb-tester/requirements.txt

@@ -4,6 +4,6 @@ nbconvert~=7.16.0
 nbformat~=5.9.2
 ipykernel~=6.29.2
 qiskit[all]~=1.0
-qiskit-aer~=0.13.1
+qiskit-aer~=0.14.0.1
 qiskit-ibm-runtime~=0.22.0
 squeaky==0.7.0