Disables shellcheck errors and removes variable

Disables specific shellcheck errors to allow certain coding
patterns and removes an unused variable from the super-linter
workflow. This improves the linter's signal-to-noise ratio
and reduces unnecessary checks.

Relates to #4696

.github/linters/.shellcheckrc

@@ -0,0 +1 @@
+disable=SC2154,SC2034

.github/workflows/action-super-linter.yml

@@ -49,5 +49,5 @@ jobs:
           VALIDATE_SHELL_SHFMT: false
           VALIDATE_TERRAFORM_TERRASCAN: false
           VALIDATE_YAML_PRETTIER: false
-          BASH_FILE_NAME: ".shellcheckrc"
+