gitlab: add RADV bug report template

Reviewed-by: Timur Kristóf <timur.kristof@gmail.com>
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <!7551>

.gitlab/issue_templates/Bug Report (AMD Radeon Vulkan).md

+# AMD Radeon Vulkan (RADV) issue template
+
+### Before submitting your bug report:
+- Check if a new version of Mesa is available which might have fixed the problem.
+- If you can, check if the latest development version (git master) works better.
+- Check if your bug has already been reported here.
+- For any logs, backtraces, etc - use [code blocks](https://docs.gitlab.com/ee/user/markdown.html#code-spans-and-blocks)
+- As examples of good bug reports you may review one of these - #2598, #2615, #2608
+
+
+Otherwise, fill the requested information below.
+And please remove anything that doesn't apply to keep things readable :)
+
+
+### Description
+
+Describe what you are doing, what you expect and what you're
+seeing instead. How frequent is the issue? Is it a one time occurrence? Does it appear multiple times but randomly? Can you easily reproduce it?
+
+"It doesn't work" usually is not a helpful description of an issue.
+The more detail about how things are going wrong, the better.
+
+### Screenshots/video files
+
+For rendering errors, attach screenshots of the problem and (if possible) of how it should look. For freezes, it may be useful to provide a screenshot of the affected game scene. Prefer screenshots over videos.
+
+### Log files (for system lockups / game freezes / crashes)
+
+- Backtrace (for crashes)
+- Output of `dmesg`
+- Hang reports: Run with `RADV_DEBUG=hang` and attach the files created in `$HOME/radv_dumps_*/`
+
+### Steps to reproduce
+
+How can Mesa developers reproduce the issue? When reporting a game issue, start explaining from a fresh save file and don't assume prior knowledge of the game's story.
+
+Example:
+
+1. `Start new game and enter second mission (takes about 10 minutes)`
+2. `Talk to the NPC called "Frank"`
+3. `Observe flickering on Frank's body`
+
+### System information
+
+Please post `inxi -GSC -xx` output ([fenced with triple backticks](https://docs.gitlab.com/ee/user/markdown.html#code-spans-and-blocks)) OR fill information below manually
+
+
+- OS: (`cat /etc/os-release | grep "NAME"`)
+- GPU: (`lspci -nn | grep VGA` or `lshw -C display -numeric`)
+- Kernel version: (`uname -a`)
+- Mesa version: (`glxinfo -B | grep "OpenGL version string"`)
+- Desktop environment: (`env | grep XDG_CURRENT_DESKTOP`)
+
+#### If applicable
+- Xserver version: (`sudo X -version`)
+- DXVK version:
+- Wine/Proton version:
+
+
+### Regression
+
+Did it used to work in a previous Mesa version? It can greatly help to know when the issue started.
+
+
+### API captures (if applicable, optional)
+
+Consider recording a [GFXReconstruct](https://github.com/LunarG/gfxreconstruct/blob/dev/USAGE_desktop.md) (preferred), [RenderDoc](https://renderdoc.org/), or [apitrace](https://github.com/apitrace/apitrace/blob/master/docs/USAGE.markdown) capture of the issue with the RADV driver active. This can tremendously help when debugging issues, but you're still encouraged to report issues if you can't provide a capture file.
+
+### Further information (optional)
+
+Does the issue reproduce with the LLVM backend (`RADV_DEBUG=llvm`) or on the AMDGPU-PRO drivers?
+
+Does your environment set any of the variables `ACO_DEBUG`, `RADV_DEBUG`, and `RADV_PERFTEST`?