Fix SmoothQuant regex to match q_a_proj in DeepSeek/GLM-5 (#2421)

Fixes #2420
The balance_layers pattern re:.*q_proj in
DEEPSEEK_V2_SMOOTHQUANT_MAPPINGS does not match q_a_proj (used by
DeepSeek V2/V3 and GLM-5). Changed to re:.*q(_a)?_proj$ as suggested by
@brian-dellabetta.

SUMMARY:
Fix regex pattern in DEEPSEEK_V2_SMOOTHQUANT_MAPPINGS to cover both
q_proj and q_a_proj.

TEST PLAN:
Verified with Python regex that the new pattern matches both layer
names:
re.fullmatch(".*q(_a)?_proj$", "model.layers.0.self_attn.q_proj") ->
match
re.fullmatch(".*q(_a)?_proj$", "model.layers.0.self_attn.q_a_proj") ->
match

Signed-off-by: gillesturpin <turpingilles@orange.fr>
Co-authored-by: Brian Dellabetta <brian-dellabetta@users.noreply.github.com>
Co-authored-by: HDCharles <39544797+HDCharles@users.noreply.github.com>

Author: 3 people

src/llmcompressor/modifiers/transform/smoothquant/utils.py

@@ -61,7 +61,7 @@
 
 DEEPSEEK_V2_SMOOTHQUANT_MAPPINGS: list[LayerMap] = [
     LayerMap(
-        balance_layers=["re:.*q_proj", "re:.*kv_a_proj_with_mqa"],
+        balance_layers=["re:.*q(_a)?_proj$", "re:.*kv_a_proj_with_mqa"],
         smooth_layers="re:.*input_layernorm",
     ),
 ]