ref: delete unreachable upstream-fetcher modules

Stacked on the modifications PR. Now that no live code path references
the per-package fetchers, the shared HTTP/parsing helpers, the
in-process normalizer, or the example template, delete them. Pure
deletion — no behavior change.

- ~93 per-package <pkg>/releases.js fetcher modules.
- _common/{brew,fetcher,git-tag,gitea,github,github-source,
  githubish,githubish-source}.js shared HTTP/parsing helpers.
- _webi/normalize.js in-process normalization layer (cache files
  arrive normalized from webicached).
- _example/releases.js fetcher template for new packages.

The Go cache daemon (webicached) is now the sole producer of release
metadata; the Node process never makes an upstream request.

postgres/releases.js

@@ -1,129 +0,0 @@
-'use strict';
-
-let Releases = module.exports;
-
-var Github = require('../_common/github.js');
-var owner = 'bnnanet';
-var repo = 'postgresql-releases';
-
-let originalReleases = {
-  _names: ['PostgreSQL', 'postgresql', 'Postgres', 'postgres', 'binaries'],
-  releases: [
-    {
-      name: 'postgresql-10.12-1-linux-x64-binaries.tar.gz',
-      version: '10.12',
-      lts: false,
-      channel: 'stable',
-      date: '',
-      os: 'linux',
-      arch: 'amd64',
-      libc: 'gnu',
-      ext: 'tar',
-      download: '',
-    },
-    {
-      name: 'postgresql-10.12-1-linux-binaries.tar.gz',
-      version: '10.12',
-      lts: false,
-      channel: 'stable',
-      date: '',
-      os: 'linux',
-      arch: 'x86',
-      libc: 'gnu',
-      ext: 'tar',
-      download: '',
-    },
-    {
-      name: 'postgresql-10.12-1-osx-binaries.zip',
-      version: '10.12',
-      lts: false,
-      channel: 'stable',
-      date: '',
-      os: 'macos',
-      arch: 'amd64',
-      ext: 'zip',
-      download: '',
-    },
-    {
-      name: 'postgresql-10.13-1-osx-binaries.zip',
-      version: '10.13',
-      lts: false,
-      channel: 'stable',
-      date: '',
-      os: 'macos',
-      arch: 'amd64',
-      ext: 'zip',
-      download: '',
-    },
-    {
-      name: 'postgresql-11.8-1-osx-binaries.zip',
-      version: '11.8',
-      lts: false,
-      channel: 'stable',
-      date: '',
-      os: 'macos',
-      arch: 'amd64',
-      ext: 'zip',
-      download: '',
-    },
-    {
-      name: 'postgresql-12.3-1-osx-binaries.zip',
-      version: '12.3',
-      lts: false,
-      channel: 'stable',
-      date: '',
-      os: 'macos',
-      arch: 'amd64',
-      ext: 'zip',
-      download: '',
-    },
-  ].map(function (rel) {
-    //@ts-ignore - it's a special property
-    rel._version = `${rel.version}-1`;
-    rel.download = `https://get.enterprisedb.com/postgresql/${rel.name}?ls=Crossover&type=Crossover`;
-    return rel;
-  }),
-  download: '',
-};
-
-Releases.latest = async function () {
-  let all = await Github.getDistributables(null, owner, repo);
-
-  /** @type {Array<Awaited<ReturnType<typeof Github.getDistributables>>>[Number]["releases"]} */
-  let distributables = [];
-  for (let dist of all.releases) {
-    console.log(dist);
-    console.log(dist.name, 'niche', /psql|baseline/.test(dist.name));
-    let isNiche = /psql|baseline/.test(dist.name);
-    if (isNiche) {
-      continue;
-    }
-
-    // REL_17_0 => 17.0
-    dist.version = dist.version.replace(/REL_/g, '');
-    dist.version = dist.version.replace(/_/g, '.');
-
-    let isHardMusl = dist.name.includes('musl');
-    if (isHardMusl) {
-      Object.assign(dist, { libc: 'musl', _musl: true });
-    }
-    distributables.push(dist);
-  }
-
-  all.releases = distributables;
-
-  Object.assign(all, { _names: originalReleases._names });
-  //@ts-ignore - mixing old and new release types
-  all.releases = all.releases.concat(originalReleases.releases);
-
-  return all;
-};
-
-if (module === require.main) {
-  Releases.latest().then(function (all) {
-    let normalize = require('../_webi/normalize.js');
-    all = normalize(all);
-    let json = JSON.stringify(all, null, 2);
-    console.info(json);
-  });
-}