build: refactor to squeeze multiple empty lines into single empty lines

---
type: pre_commit_static_analysis_report
description: Results of running static analysis checks when committing changes.
report:
  - task: lint_filenames
    status: passed
  - task: lint_editorconfig
    status: passed
  - task: lint_markdown
    status: na
  - task: lint_package_json
    status: na
  - task: lint_repl_help
    status: na
  - task: lint_javascript_src
    status: passed
  - task: lint_javascript_cli
    status: na
  - task: lint_javascript_examples
    status: na
  - task: lint_javascript_tests
    status: na
  - task: lint_javascript_benchmarks
    status: na
  - task: lint_python
    status: na
  - task: lint_r
    status: na
  - task: lint_c_src
    status: na
  - task: lint_c_examples
    status: na
  - task: lint_c_benchmarks
    status: na
  - task: lint_c_tests_fixtures
    status: na
  - task: lint_shell
    status: na
  - task: lint_typescript_declarations
    status: na
  - task: lint_typescript_tests
    status: na
  - task: lint_license_headers
    status: passed
---

Author: Planeshifter

lib/node_modules/@stdlib/_tools/changelog/generate/lib/breaking_changes.js

@@ -39,34 +39,48 @@ var RE_YAML_DELIMITER = /^\s*---\s*$/;
 // FUNCTIONS //
 
 /**
-* Strips YAML frontmatter blocks from text lines.
+* Processes commit message text by removing YAML blocks and squashing multiple empty lines into a single empty line.
 *
 * @private
 * @param {Array<string>} lines - text lines to process
-* @returns {Array<string>} text lines without YAML blocks
+* @returns {Array<string>} text lines without YAML blocks and multiple empty lines
 */
 function stripYamlBlocks( lines ) {
-	var result;
+	var previousLineEmpty;
+	var trimmed;
 	var inYaml;
+	var out;
 	var i;
 
-	result = [];
+	previousLineEmpty = false;
+	out = [];
 	inYaml = false;
 
 	for ( i = 0; i < lines.length; i++ ) {
 		// Check for YAML delimiter (---) with optional whitespace:
-		if ( RE_YAML_DELIMITER.test( lines[i] ) ) {
+		if ( RE_YAML_DELIMITER.test( lines[ i ] ) ) {
 			inYaml = !inYaml; // Toggle YAML block state
 			continue;
 		}
 
 		// Only include lines that are not part of YAML blocks:
 		if ( !inYaml ) {
-			result.push( lines[i] );
+			trimmed = trim( lines[ i ] );
+
+			if ( trimmed === '' ) {
+				// Only add an empty line if the previous line wasn't empty:
+				if ( !previousLineEmpty && out.length > 0 ) {
+					previousLineEmpty = true;
+					out.push( '' );
+				}
+			} else {
+				previousLineEmpty = false;
+				out.push( lines[ i ] ); // Preserve original line formatting
+			}
 		}
 	}
 
-	return result;
+	return out;
 }
 
 /**
@@ -87,31 +101,19 @@ function stripYamlBlocks( lines ) {
 */
 function formatBreakingChange( note ) {
 	var contentLines;
-	var trimmedLine;
+	var textLines;
 	var firstLine;
 	var restLines;
-	var textLines;
 	var hash;
 	var out;
-	var i;
 
 	textLines = note.text.split( reEOL.REGEXP );
 	contentLines = stripYamlBlocks( textLines );
-	firstLine = '';
-	restLines = [];
-	hash = trim( note.hash );
 
-	for ( i = 0; i < contentLines.length; i++ ) {
-		trimmedLine = trim( contentLines[i] );
-		if ( trimmedLine !== '' ) {
-			// If this is our first non-empty line, it's the firstLine...
-			if ( firstLine === '' ) {
-				firstLine = trimmedLine;
-			} else {
-				restLines.push( trimmedLine );
-			}
-		}
-	}
+	// If we have content, first element is the first line:
+	firstLine = contentLines[ 0 ] || '';
+	restLines = contentLines.slice( 1 );
+	hash = trim( note.hash );
 
 	// Construct output string - use a single string concatenation when possible
 	out = '-   [`' + hash.substring( 0, 7 ) + '`](' + STDLIB_GITHUB_URL + '/' + hash + '): ' + firstLine;