build: PyPI doesn't like direct installation from git

Fixes:

ERROR    HTTPError: 400 Bad Request from https://upload.pypi.org/legacy/
         Invalid value for requires_dist. Error: Can't have direct dependency:
         "quantum-pecos @
         git+https://github.com/PECOS-packages/PECOS.git@e2e-testing ; extra ==
         'phirc'"

README.md

@@ -22,7 +22,9 @@ Just issue `pip install pytket-phir` to obtain the latest stable release.
 
 The package includes a tool for emulating QASM files from the command line using PECOS.
 
-PECOS needs to be installed using `pip install .[phirc]` for the CLI to work.
+NOTE: PECOS currently requires installation using
+`pip install "quantum-pecos@git+https://github.com/PECOS-packages/PECOS.git@e2e-testing"`
+for the CLI to work.
 
 ```sh
 ❯ phirc -h

docs/source/pytket.phir.rst

@@ -21,14 +21,6 @@ pytket.phir.api module
    :undoc-members:
    :show-inheritance:
 
-pytket.phir.cli module
-----------------------
-
-.. automodule:: pytket.phir.cli
-   :members:
-   :undoc-members:
-   :show-inheritance:
-
 pytket.phir.machine module
 --------------------------
 

pyproject.toml

@@ -27,7 +27,7 @@ dependencies = ["phir>=0.1.6", "pytket"]
 
 [project.optional-dependencies]
 docs = ["sphinx", "pydata_sphinx_theme"]
-phirc = ["quantum-pecos@git+https://github.com/PECOS-packages/PECOS.git@e2e-testing"]
+# phirc = ["quantum-pecos@git+https://github.com/PECOS-packages/PECOS.git@e2e-testing"]
 tests = ["pytest"]
 
 [project.scripts]