Fix text color on job log in dark mode

Reset yiq-text-color to correct values since the bootstrap
defaults are inverted when we override $white and $gray-950

Original values https://github.com/twbs/bootstrap/blob/v4-dev/scss/_variables.scss#L98

app/assets/stylesheets/framework/job_log.scss

@@ -5,7 +5,7 @@
   font-size: 13px;
   word-break: break-all;
   word-wrap: break-word;
-  color: $gl-text-color-inverted;
+  color: color-yiq($builds-trace-bg);
   border-radius: $border-radius-small;
   min-height: 42px;
   background-color: $builds-trace-bg;

app/assets/stylesheets/themes/_dark.scss

@@ -115,6 +115,9 @@ $secondary: $gray-600;
 $issues-today-bg: #333838;
 $issues-today-border: #333a40;
 
+$yiq-text-dark: $gray-50;
+$yiq-text-light: $gray-950;
+
 .gl-label {
   filter: brightness(0.9) contrast(1.1);
 }

changelogs/unreleased/psi-job-log-text.yml

+---
+title: Fix job log text color in dark mode
+merge_request: 35387
+author:
+type: fixed