Modernize build commands for setuptools 80+ compatibility (#8728)

## Description
This PR modernizes MONAI's build and installation commands to be
compatible with setuptools 80+, which removed the deprecated `setup.py
develop --uninstall` command as part of PEP 660 modernization.

## Changes
- **runtests.sh**: Updated `compile_cpp()` and `clean_py()` functions to
use `pip` commands instead of deprecated `setup.py develop`
- **requirements-min.txt**: Removed setuptools upper bound (<=79.0.1)
for Python 3.12+
- **docs/source/installation.md**: Updated editable installation
examples to use modern `pip install -e .`
- **.github/workflows/pythonapp.yml**: Updated CI workflow to use pip
commands

## Rationale
In setuptools 80+, the `setup.py develop --uninstall` command was
removed because the build system now delegates to pip for all
installation/uninstallation operations (PEP 660). The old approach:
- `python setup.py develop` → Now: `pip install -e .`
- `python setup.py develop --uninstall` → Now: `pip uninstall -y monai`

## Testing
- Verified bash syntax in runtests.sh has no errors
- Confirmed no remaining references to deprecated commands
- All changes maintain functional equivalence with modern pip approach

## Types of changes
- [x] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [x] Documentation update

Fixes #8439

---------

Signed-off-by: Mohamed Salah <eng.mohamed.tawab@gmail.com>
Co-authored-by: Eric Kerfoot <17726042+ericspod@users.noreply.github.com>

Author: engmohamedsalah

.github/workflows/pythonapp.yml

@@ -87,12 +87,12 @@ jobs:
         cat "requirements-dev.txt"
         python -m pip install --no-build-isolation -r requirements-dev.txt
         python -m pip list
-        python setup.py develop  # test no compile installation
+        python -m pip install -e .  # test no compile installation
       shell: bash
     - name: Run compiled (${{ runner.os }})
       run: |
-        python setup.py develop --uninstall
-        BUILD_MONAI=1 python setup.py develop  # compile the cpp extensions
+        python -m pip uninstall -y monai
+        BUILD_MONAI=1 python -m pip install -e .  # compile the cpp extensions
       shell: bash
     - name: Run quick tests (CPU ${{ runner.os }})
       run: |

docs/source/installation.md

@@ -135,23 +135,23 @@ You can install it by running:
 
 ```bash
 cd MONAI/
-python setup.py develop
+pip install -e .
 ```
 
 or, to build with MONAI C++/CUDA extensions and install:
 
 ```bash
 cd MONAI/
-BUILD_MONAI=1 python setup.py develop
+BUILD_MONAI=1 pip install -e .
 # for MacOS
-BUILD_MONAI=1 CC=clang CXX=clang++ python setup.py develop
+BUILD_MONAI=1 CC=clang CXX=clang++ pip install -e .
 ```
 
 To uninstall the package please run:
 
 ```bash
 cd MONAI/
-python setup.py develop --uninstall
+pip uninstall -y monai
 
 # to further clean up the MONAI/ folder (Bash script)
 ./runtests.sh --clean

runtests.sh

@@ -145,9 +145,9 @@ function compile_cpp {
     ${cmdPrefix}"${PY_EXE}" -m pip uninstall -y monai
     if [[ "$OSTYPE" == "darwin"* ]];
     then  # clang for mac os
-        CC=clang CXX=clang++ ${cmdPrefix}"${PY_EXE}" setup.py develop --user
+        BUILD_MONAI=1 CC=clang CXX=clang++ ${cmdPrefix}"${PY_EXE}" -m pip install -e .
     else
-        ${cmdPrefix}"${PY_EXE}" setup.py develop --user
+        BUILD_MONAI=1 ${cmdPrefix}"${PY_EXE}" -m pip install -e .
     fi
 }