Fix DeprecationWarning in regexReplace filter test

Python 3.14 raises DeprecationWarning for invalid escape sequences
processed through Jinja2's unicode-escape codec. The string literal
'\d' inside the Jinja2 template triggers this; '\\d' makes Jinja2
decode it to \d correctly without the warning.

Author: bschwedler

posit-bakery/test/config/templating/test_render.py

@@ -67,7 +67,7 @@ def test_regexReplace_filter(self):
         env = jinja2_env()
         assert env.from_string("{{ 'hello world' | regexReplace('world', 'there') }}").render() == "hello there"
         assert env.from_string("{{ 'foo-bar-baz' | regexReplace('-', '_') }}").render() == "foo_bar_baz"
-        assert env.from_string(r"{{ '123-456-789' | regexReplace('\d', 'X') }}").render() == "XXX-XXX-XXX"
+        assert env.from_string(r"{{ '123-456-789' | regexReplace('\\d', 'X') }}").render() == "XXX-XXX-XXX"
 
 
 def test_render_template():