language/*: only check required deps in detected_*_shebang

Otherwise, we rewrite this even when we have a e.g. build or test
dependency on NodeJS.

See context in:
Homebrew/homebrew-core#176257 (comment)

Library/Homebrew/language/node.rb

@@ -109,7 +109,7 @@ def node_shebang_rewrite_info(node_path)
 
  sig { params(formula: Formula).returns(Utils::Shebang::RewriteInfo) }
  def detected_node_shebang(formula = T.cast(self, Formula))
- node_deps = formula.deps.map(&:name).grep(/^node(@.+)?$/)
+ node_deps = formula.deps.select(&:required?).map(&:name).grep(/^node(@.+)?$/)
  raise ShebangDetectionError.new("Node", "formula does not depend on Node") if node_deps.empty?
  raise ShebangDetectionError.new("Node", "formula has multiple Node dependencies") if node_deps.length > 1
 

Library/Homebrew/language/perl.rb

@@ -28,7 +28,7 @@ def perl_shebang_rewrite_info(perl_path)
 
  sig { params(formula: Formula).returns(Utils::Shebang::RewriteInfo) }
  def detected_perl_shebang(formula = T.cast(self, Formula))
- perl_deps = formula.declared_deps.select { |dep| dep.name == "perl" }
+ perl_deps = formula.declared_deps.select { |dep| dep.required? && dep.name == "perl" }
  raise ShebangDetectionError.new("Perl", "formula does not depend on Perl") if perl_deps.empty?
 
  perl_path = if perl_deps.any? { |dep| !dep.uses_from_macos? || !dep.use_macos_install? }

Library/Homebrew/language/python.rb

@@ -128,7 +128,7 @@ def detected_python_shebang(formula = T.cast(self, Formula), use_python_from_pat
  python_path = if use_python_from_path
  "/usr/bin/env python3"
  else
- python_deps = formula.deps.map(&:name).grep(/^python(@.+)?$/)
+ python_deps = formula.deps.select(&:required?).map(&:name).grep(/^python(@.+)?$/)
  raise ShebangDetectionError.new("Python", "formula does not depend on Python") if python_deps.empty?
  if python_deps.length > 1
  raise ShebangDetectionError.new("Python", "formula has multiple Python dependencies")