Update versioning workflow for releases

[srinivas9804]

The current workflow needs to update the version number everytime a new release is made. This is good to keep things consistent with meson but it does add some overhead during every release. Could use something like this https://stackoverflow.com/questions/74949299/how-to-versioning-releases-in-github-actions

[ibaldin]

I think we can do better. Seems like doing something like this lets us get the string that the version is set to in top-level meson.build:

E2SAR/$ meson introspect --projectinfo build | jq .version | tr -d '"'                                        
0.2.0a1

So I think we can change the action to do this to grab the version we are building (and we can/should make sure there is a tag matching that version).

[eli-schwartz]

project('E2SAR', 'cpp',
        version: '0.1.5', default_options : ['cpp_std=c++17'])

can be:

project('E2SAR', 'cpp',
        version: files('VERSION.txt'), default_options : ['cpp_std=c++17'])

... permitting you to maintain the version in a single text file containing nothing the version number on a single line. That's easy to parse anywhere e.g. in scripts and possibly, depending on what types of files also need the version number you may be able to single-source the information everywhere.