Society seems to be going in the opposite direction (e.g. self-checkouts at supermarkets, government services being available over the internet, online shops, online gaming, etc.)
But if you insist: the best thing a government can do is to have some civic service which any kind of person can be called to do (not just the unenemployed, the retired, or other such people that the govt. wants to “keep busy”). There’s nothing that bonds more (between strangers) than reluctantly having to do some task because either Nature or Government is forcing you to. ;)
Or just facilitate the creation and running of volunteer groups.
A government doesn't actually need to be the director or curator of a country's culture, even though it is in a position of great influence.
A government, particularly local government, will strongly direct community culture whether it seeks to or not. Particularly zoning and construction planning will influence the space people do or do not have available for meeting and socializing. The trend in the US seems to be to spread people out and privatize most or all "public" social spaces. I wouldn't attribute this shift to governments intentionally trying to shift culture to being more isolated, but that is the outcome regardless. This means that the only real counter to this shift is to get governments to consider the social impact of planning and factor it into their decision making.
If your daily or weekly life involves going to a Church, synagogue, it something else- you have a built in structure for being around and interacting with people.
It's interesting for me to think about - religion declined as percentage of population in recent decades but I suspect in the long run (1/2 generations) religion provides enough antidote to things that plague secular society (isolation, depression, childlessness) that it might swing the percentages in the other direction.
And for a lot of unhealthy behavior too.
Then I got married and had kids and realized that this "boring mainstream" life is peak experience.
In other words, it took me 20 extra years to arrive at a life that someone brought up religious would just consider the default.
Like I said, I am sure there are extreme cases and I am not talking about those. Just talking about the base case, religious folks' default life path feels healthier.
It, among other things, may mean marrying at 18 to a partner you dated very shortly and never seen alone. Because anything else is sin. And then you are locked in for life.
And that is not nearly the same as marrying when mature and having partner you actually know. It can be special kind of hell.