Simplify build and release workflow

[sitiom]

• Combine build.yml and release.yml as separate jobs in ci.yml so that the build.yml code is not duplicated
• Remove unnecessary variable assignments
• Use https://github.com/battila7/get-version-action to get the current tag action
• Build all, then create a draft release using https://github.com/softprops/action-gh-release. You then have to publish it yourself manually. Resolves Add Winget Releaser workflow #102 (comment).
• iscc is already in the PATH, do not call directly to its absolute path. Also, build the installer to RELEASE_DIR.
• Add Dependabot to automatically update dependencies

Everything is tested to be working as intended in my fork.

[xmine64]

Nice work, thanks

[sitiom]

@xmine64 bump

[xmine64]

Build failed but I merge anyway, will fix if it still fails later.

[xmine64]

winget releaser doesn't work👀 matched installers are [] I guess we don't have access to artifacts from winget.yml workflow.

[sitiom]

I think the installer regex is wrong, will fix.

[sitiom]

@xmine64 I forgot an extra step: You should keep the fork regularly updated with Pull. Otherwise, it will eventually try to update the old workflows without the workflow scope, resulting in an error.

[xmine64]

Thanks, done.