How to extract all .htaccess files from a tarball

It won't be fast, especially for a large tarball with lots of files, but in bash you can do this:

tar -tzf tarball.tgz | while IFS= read -r file; do
    tar --no-recursion -xzf tarball.tgz -- "$file"
    gzip -- "$file"
done

The first tar command extracts the names of the files in the tarball, and passes those names to a while read ... loop. The file name is then passed to a second tar command that extracts just that file, which is then compressed before the next file is extracted. The --no-recursion flag is used so trying to extract a directory doesn't extract all the files under that directory, which is what tar would normally do.

You'll still need enough free space to store somewhat more than the original size of the compressed tarball.

Extracting the tarball you have in your question will create the directory mediawiki-1.33.0 which contains the following sub-directories:

$ tree -dL 1 mediawiki-1.33.0
mediawiki-1.33.0
├── cache
├── docs
├── extensions
├── images
├── includes
├── languages
├── maintenance
├── mw-config
├── resources
├── skins
├── tests
└── vendor

12 directories

Assuming these are also the directories you need in a proper mediawiki installation, all you need to do is:

1. Backup the files you want to keep, using -p to keep the permissions, ownership and timestamps unchanged.

   cp -p LocalSettings.php robots.txt .htaccess example.com.png googlec69e044fede13fdc.html /some/other/path
   

2. Extract the tarball

   tar xvzf mediawiki-1.33.0.tar.gz
   

3. Copy the files to wherever they should be

   cp -a mediawiki-1.33.0/* /path/to/mediawiki/instrallation
   

   This will overwrite any existing files.

4. Copy the backups back to their original locations

   cp -p /some/other/path/LocalSettings.php /original/path