User agent: don't include the patch number in the Firefox version

The Firefox version in the user agent doesn't include the patch version: 106.0 not 106.0.2

Close #1914

searx/data/useragents.json

@@ -1,11 +1,6 @@
 {
     "versions": [
-        "106.0.2",
-        "106.0.1",
         "106.0",
-        "105.0.3",
-        "105.0.2",
-        "105.0.1",
         "105.0"
     ],
     "os": [

searxng_extra/update/update_firefox_version.py

@@ -64,8 +64,11 @@ def fetch_firefox_last_versions():
     major_list = (major_last, major_last - 1)
     for version in versions:
         major_current = version.version[0]
+        minor_current = version.version[1]
         if major_current in major_list:
-            result.append(version.vstring)
+            user_agent_version = f'{major_current}.{minor_current}'
+            if user_agent_version not in result:
+                result.append(user_agent_version)
 
     return result