glsl/float64: Bump #version to 400

An earlier commit tried to make this shader compatible with GLSL 3.30,
but it requires, GL_ARB_gpu_shader_int64, which requires GLSL 4.00 and
GL 4.0 according to the extension spec.  So we were failing to enable
the required extension, breaking compilation of this shader.

The original intention of that patch was to get this working on zink,
which at the time only supported GL 3.3.  But now it supports later
OpenGL versions, so we don't need to do this any longer.  Rather than
revert the patch and raise the version all the way back to 430, just
bump it to the require 400 at Ian Romanick's suggestion.

Fixes: 4d47b22bf0 ("glsl/float64: make this compatible with glsl 330")
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/3991
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9351>
(cherry picked from commit a48151ffad)

.pick_status.json

@@ -1399,7 +1399,7 @@
         "description": "glsl/float64: Bump #version to 400",
         "nominated": true,
         "nomination_type": 1,
-        "resolution": 0,
+        "resolution": 1,
         "master_sha": null,
         "because_sha": "4d47b22bf007413274cabac264122ab7e428fe7d"
     },

src/compiler/glsl/float64.glsl

@@ -40,7 +40,7 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
-#version 330
+#version 400
 #extension GL_ARB_gpu_shader_int64 : enable
 #extension GL_ARB_shader_bit_encoding : enable
 #extension GL_EXT_shader_integer_mix : enable