Configures shellcheckrc filename

Configures the Super-Linter action to use `.shellcheckrc` as the
BASH_FILE_NAME. This ensures that shellcheck uses the correct
configuration file for bash script linting.

Fixes #4696

Author: dgibbs64

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

@@ -49,3 +49,5 @@ jobs:
           VALIDATE_SHELL_SHFMT: false
           VALIDATE_TERRAFORM_TERRASCAN: false
           VALIDATE_YAML_PRETTIER: false
+          BASH_FILE_NAME: ".shellcheckrc"
+