Add a script to add the latest miniforge and mambaforge versions

This takes inspiration from the similar script for miniconda, but it
simplifies in a couple of ways:

1. Use the GitHub Releases API instead of scraping HTML.
2. Don't perform a diff, simply add the latest release.

Lots of intermediate miniconda releases have been skipped in the past,
and it doesn't seem particularly valuable to backfill those.

plugins/python-build/scripts/add_miniforge.py

@@ -0,0 +1,104 @@
+#!/usr/bin/env python3
+'Adds the latest miniforge and mambaforge releases.'
+from pathlib import Path
+import logging
+import os
+import string
+
+import requests
+
+logger = logging.getLogger(__name__)
+logging.basicConfig(level=os.environ.get('LOGLEVEL', 'INFO'))
+
+MINIFORGE_REPO = 'conda-forge/miniforge'
+PYTHON_VERSION = '310'
+DISTRIBUTIONS = ['miniforge', 'mambaforge']
+
+install_script_fmt = """
+case "$(anaconda_architecture 2>/dev/null || true)" in
+{install_lines}
+* )
+  {{ echo
+    colorize 1 "ERROR"
+    echo ": The binary distribution of {flavor} is not available for $(anaconda_architecture 2>/dev/null || true)."
+    echo
+  }} >&2
+  exit 1
+  ;;
+esac
+""".lstrip()
+
+install_line_fmt = """
+"{os}-{arch}" )
+  install_script "{filename}" "{url}#{sha}" "miniconda" verify_py{py_version}
+  ;;
+""".strip()
+
+here = Path(__file__).resolve()
+out_dir: Path = here.parent.parent / "share" / "python-build"
+
+def download_sha(url):
+    logger.debug('Downloading SHA file %(url)s', locals())
+    tup = tuple(reversed(requests.get(url).text.replace('./', '').rstrip().split()))
+    logger.debug('Got %(tup)s', locals())
+    return tup
+
+def create_spec(filename, sha, url):
+    flavor_with_suffix, version, subversion, os, arch = filename.replace('.sh', '').split('-')
+    suffix = flavor_with_suffix[-1]
+
+    if suffix in string.digits:
+        flavor = flavor_with_suffix[:-1]
+    else:
+        flavor = flavor_with_suffix
+
+    spec = {
+        'filename': filename,
+        'sha': sha,
+        'url': url,
+        'py_version': PYTHON_VERSION,
+        'flavor': flavor,
+        'os': os,
+        'arch': arch,
+        'installer_filename': f'{flavor_with_suffix.lower()}-{version}-{subversion}',
+    }
+
+    logger.debug('Created spec %(spec)s', locals())
+
+    return spec
+
+def supported(filename):
+    return ('pypy' not in filename) and ('Windows' not in filename)
+
+def add_version(release):
+    download_urls = { f['name']: f['browser_download_url'] for f in release['assets'] }
+    shas = dict([download_sha(url) for (name, url) in download_urls.items() if name.endswith('.sha256')])
+    specs = [create_spec(filename, sha, download_urls[filename]) for (filename, sha) in shas.items() if supported(filename)]
+
+    for distribution in DISTRIBUTIONS:
+        distribution_specs = [spec for spec in specs if distribution in spec['flavor'].lower()]
+        count = len(distribution_specs)
+
+        if count > 0:
+            output_file = out_dir / distribution_specs[0]['installer_filename']
+
+            logger.info('Writing %(count)d specs for %(distribution)s to %(output_file)s', locals())
+
+            script_str = install_script_fmt.format(
+                install_lines="\n".join([install_line_fmt.format_map(s) for s in distribution_specs]),
+                flavor=distribution_specs[0]['flavor'],
+            )
+
+            with open(output_file, 'w') as f:
+                f.write(script_str)
+        else:
+            logger.info('Did not find specs for %(distribution)s', locals())
+
+for release in requests.get(f'https://api.github.com/repos/{MINIFORGE_REPO}/releases').json():
+    version = release['tag_name']
+
+    logger.info('Looking for %(version)s in %(out_dir)s', locals())
+
+    if not list(out_dir.glob(f'*-{version}')):
+        logger.info('Downloading %(version)s', locals())
+        add_version(release)