Upgrade to Bootstrap 4.6.2 (module install)

[deining]

This PR syncs the versions of dependencies between Hugo modules and npm packages, as requested in #1182.
More concrete, it

• upgrades module/package FontAwesome to version 6..2.0 (npm + module install),
• upgrades package hugo-extended to hugo version 0..104.3 (npm install).
• updates go to latest version 1.19.2

[chalin]

@deining - could you resolve the conflicts? I could do it, but it's probably safer for you to do so. Thanks. I'll merge soon afterwards so that this PR doesn't get conflicts again!

[deining]

@deining - could you resolve the conflicts?

Done.

I'll merge soon afterwards so that this PR doesn't get conflicts again!

Glad to see this merged now!

[chalin]

Great, thanks!

[chalin]

For the record, after pulling this change in, and rerunning npm install, there are the differences is the generated site files:

$ (cd userguide/public && git diff -bw --ignore-blank-lines -I "Hugo 0\.") | grep ^diff | grep -Ev '(.xml|_print)'
diff --git a/scss/main.css b/scss/main.css
diff --git a/scss/main.css.map b/scss/main.css.map
diff --git a/webfonts/fa-brands-400.ttf b/webfonts/fa-brands-400.ttf
diff --git a/webfonts/fa-brands-400.woff2 b/webfonts/fa-brands-400.woff2
diff --git a/webfonts/fa-regular-400.ttf b/webfonts/fa-regular-400.ttf
diff --git a/webfonts/fa-regular-400.woff2 b/webfonts/fa-regular-400.woff2
diff --git a/webfonts/fa-solid-900.ttf b/webfonts/fa-solid-900.ttf
diff --git a/webfonts/fa-solid-900.woff2 b/webfonts/fa-solid-900.woff2
diff --git a/webfonts/fa-v4compatibility.ttf b/webfonts/fa-v4compatibility.ttf
diff --git a/webfonts/fa-v4compatibility.woff2 b/webfonts/fa-v4compatibility.woff2