Ignition Edifice import failed: lack of one of the physics4 packages

[j-rivero]

After #131 the import of Ignition Edifice was not complete, failing with the error:

$ aptitude install ignition-edifice
...
The following packages have unmet dependencies:
 libignition-physics4-dev : Depends: libignition-physics4-heightmap-dev (= 4.3.0-1~focal) which is a virtual package and is not provided by any available package

 libignition-physics4-dartsim-dev : Depends: libignition-physics4-heightmap-dev (= 4.3.0-1~focal) which is a virtual package and is not provided by any available package

The following actions will resolve these dependencies:

     Keep the following packages at their current version:
1)     libignition-physics4-dartsim-dev [Not Installed]   
2)     libignition-physics4-dev [Not Installed]    

libignition-physics4-heightmap-dev was missing from the import but nor our CI nor our importer (really the same aptly calls) was not able to detect it. It is being listed a standard Depends: of libignition-physics4-dartsim-dev listed in the config file.

reported by @luca-della-vedova @chapulina

[chapulina]

For completeness, the bullet component is also missing, but it's not causing issues because it isn't required

[chapulina]

Fixed!