Remove invalid releases automatically (#466)

Automatically remove empty releases or releases which are released in the future, regardless of the product.

Also refactored a bit releasedata.py to use better names and clarify types.

releases/pan-cortex-xdr.json

@@ -25,9 +25,6 @@
       "releaseDate": "2024-04-14",
       "eol": "2025-02-05"
     },
-    "8.3-ce": {
-      "name": "8.3-ce"
-    },
     "8.3": {
       "name": "8.3",
       "releaseDate": "2024-02-11",
@@ -48,12 +45,6 @@
       "releaseDate": "2023-03-05",
       "eol": "2023-12-19"
     },
-    "7.9.103-ce": {
-      "name": "7.9.103-ce"
-    },
-    "7.9-ce": {
-      "name": "7.9-ce"
-    },
     "7.9": {
       "name": "7.9",
       "releaseDate": "2022-12-04",
@@ -74,9 +65,6 @@
       "releaseDate": "2021-12-05",
       "eol": "2022-09-05"
     },
-    "7.5-ce": {
-      "name": "7.5-ce"
-    },
     "7.5": {
       "name": "7.5",
       "releaseDate": "2021-08-22",