[unity] Add automation for LTS releases

Fetches the Unity LTS releases from the Unity website. Non-LTS releases are not listed there,
so this automation is only partial.

src/unity.py

@@ -0,0 +1,43 @@
+from bs4 import BeautifulSoup
+from common import endoflife
+
+# Fetches the Unity LTS releases from the Unity website. Non-LTS releases are not listed there,
+# so this automation is only partial.
+#
+# This script iterates over all pages of the Unity LTS releases page, which is paginated.
+# It keeps fetching the next page until there is no next page link.
+
+PRODUCT = 'unity'
+URL = 'https://unity.com/releases/editor/qa/lts-releases'
+
+
+def fetch_releases(releases, url) -> str:
+    print(url)
+    response = endoflife.fetch_url(url)
+    soup = BeautifulSoup(response, features="html5lib")
+
+    for release in soup.find_all('div', class_='component-releases-item__show__inner-header'):
+        version = release.find('h4').find('span').text
+        date = release.find('time').attrs['datetime'].split('T')[0]
+        releases[version] = date
+        print(f"{version}: {date}")
+
+    next_link = soup.find('a', {"rel": "next"})
+    if next_link:
+        return URL + next_link.attrs['href']
+
+    return None
+
+
+print(f"::group::{PRODUCT}")
+all_releases = {}
+next_page_url = URL
+
+while next_page_url:
+    next_page_url = fetch_releases(all_releases, next_page_url)
+
+endoflife.write_releases(PRODUCT, dict(
+    # sort by version then date (asc)
+    sorted(all_releases.items(), key=lambda x: (x[0], x[1]))
+))
+print("::endgroup::")