build(docs-infra): unpin certain dependencies of the preview server (#36837)
build(docs-infra): unpin certain dependencies of the preview server (#36837)

Previously, in order to remain as deterministic as possible, the
Dockerfile for the preview server Docker image had all dependencies
pinned to specific versions. It turns out that some packages (such as
`nginx`, `nodejs`, and `openssl` - potentially others too) make older
versions unavailable on the repositories once a newer version is
available.

See for example:
- https://github.com/nodesource/distributions/issues/33
- https://askubuntu.com/questions/715104/how-can-i-downgrade-openssl-via-apt-get

This commit, therefore, removes the exact versions for these packages.
The latest versions will be installed everytime the Docker image is
built (subject to Docker caching).

PR Close #36837

manekinekko/angular,alxhub/angular,angular/angular,mgechev/angular,blesh/angular,angular-indonesia/angular,alxhub/angular,IdeaBlade/angular,manekinekko/angular,gnomeontherun/angular,blesh/angular,shairez/angular,shairez/angular,manekinekko/angular,brandonroberts/angular,IdeaBlade/angular,gnomeontherun/angular,ocombe/angular,alxhub/angular,gdi2290/angular,shairez/angular,manekinekko/angular,filipesilva/angular,angular/angular,ocombe/angular,wKoza/angular,mgechev/angular,wKoza/angular,gdi2290/angular,brandonroberts/angular,gdi2290/angular,wKoza/angular,angular-indonesia/angular,IdeaBlade/angular,manekinekko/angular,filipesilva/angular,shairez/angular,JiaLiPassion/angular,filipesilva/angular,alxhub/angular,manekinekko/angular,gdi2290/angular,ocombe/angular,angular/angular,brandonroberts/angular,ocombe/angular,ocombe/angular,mgechev/angular,angular-indonesia/angular,angular-indonesia/angular,gdi2290/angular,IdeaBlade/angular,IdeaBlade/angular,gkalpak/angular,gdi2290/angular,JiaLiPassion/angular,mgechev/angular,wKoza/angular,filipesilva/angular,brandonroberts/angular,brandonroberts/angular,JiaLiPassion/angular,ocombe/angular,JiaLiPassion/angular,blesh/angular,gnomeontherun/angular,filipesilva/angular,wKoza/angular,blesh/angular,gkalpak/angular,brandonroberts/angular,mgechev/angular,gkalpak/angular,alxhub/angular,gkalpak/angular,blesh/angular,shairez/angular,angular/angular,wKoza/angular,gnomeontherun/angular