Fix gl_compatibility lightmap uniforms not being set

Fixes #99592

The following variables were set too early, and later code never ran..
prev_shader, prev_variant, prev_spec_constants variables

These variables were shared in two different branch conditions but were
updated inside the first one, so the second could never be true..

The condition to update lighting also should check prev_spec_constants
since it updates that uniform.

drivers/gles3/rasterizer_scene_gles3.cpp

@@ -3314,10 +3314,6 @@ void RasterizerSceneGLES3::_render_list_template(RenderListParameters *p_params,
 				}
 
 				material_storage->shaders.scene_shader.version_set_uniform(SceneShaderGLES3::OPAQUE_PREPASS_THRESHOLD, opaque_prepass_threshold, shader->version, instance_variant, spec_constants);
-
-				prev_shader = shader;
-				prev_variant = instance_variant;
-				prev_spec_constants = spec_constants;
 			}
 
 			// Pass in lighting uniforms.
@@ -3355,7 +3351,7 @@ void RasterizerSceneGLES3::_render_list_template(RenderListParameters *p_params,
 				}
 
 				// Pass light count and array of light indices for base pass.
-				if ((prev_inst != inst || prev_shader != shader || prev_variant != instance_variant) && pass == 0) {
+				if ((prev_inst != inst || prev_shader != shader || prev_variant != instance_variant || prev_spec_constants != spec_constants) && pass == 0) {
 					// Rebind the light indices.
 					material_storage->shaders.scene_shader.version_set_uniform(SceneShaderGLES3::OMNI_LIGHT_COUNT, inst->omni_light_gl_cache.size(), shader->version, instance_variant, spec_constants);
 					material_storage->shaders.scene_shader.version_set_uniform(SceneShaderGLES3::SPOT_LIGHT_COUNT, inst->spot_light_gl_cache.size(), shader->version, instance_variant, spec_constants);
@@ -3412,11 +3408,14 @@ void RasterizerSceneGLES3::_render_list_template(RenderListParameters *p_params,
 					} else if (inst->lightmap_sh) {
 						glUniform4fv(material_storage->shaders.scene_shader.version_get_uniform(SceneShaderGLES3::LIGHTMAP_CAPTURES, shader->version, instance_variant, spec_constants), 9, reinterpret_cast<const GLfloat *>(inst->lightmap_sh->sh));
 					}
-
 					prev_inst = inst;
 				}
 			}
 
+			prev_shader = shader;
+			prev_variant = instance_variant;
+			prev_spec_constants = spec_constants;
+
 			// Pass in reflection probe data
 			if constexpr (p_pass_mode == PASS_MODE_COLOR || p_pass_mode == PASS_MODE_COLOR_TRANSPARENT) {
 				if (pass == 0 && inst->reflection_probe_rid_cache.size() > 0) {