[BUG] No build flavour suffix when flavour is DEV and filesystem is dirty.

[Tirpitz93]

Printer type - [e.g. MK3S, MK3, MK2.5S, MK2.5, MK2S, MK2]

NA

Printer firmware version - [e.g. 3.8.1, 3.8.1-RC1, ...]

NA

MMU upgrade - [e.g. MMU2S, MMU2, MMU1]

MMU upgrade firmware version - [e.g. 1.0.6, 1.0.6-RC2, ...]

NA

SD card or USB/Octoprint

Please let us know if you print via SD card or USB/Octoprint
NA

Describe the bug
A clear and concise description of what the bug is.

Build issue when building a DEV flavour build from a dirty local file system.
CMAKE replaces both instances of -D in the description string with the commit count:
Input: v3.14.0-DEV1-D Results in v3.14.0-8112-DEV1-8112-D
This causes the flavour to be lost in the file suffix.

To Reproduce
Please describe steps to reproduce the behavior.

1. Tag a build with a version including the DEV flavourEG v3.14.0-DEV1
2. Modify a git-tracked file.
3. Build

Expected behavior
A clear and concise description of what you expected to happen.
Flavour string is correctly appended to the filename.

Suggested Fix
I believe I have fixed this in my fork with one line.
I will mention PR when created