Ensure log() calls from jinja ensure the msg is stringified

The simplest way to resolve [CT-2259](#7108)
and [CT-1783](#6568) in backports
to dbt-core < 1.4 is to ensure `msg` in `BaseContext.log()` is stringified.

core/dbt/context/base.py

@@ -556,6 +556,10 @@ def log(msg: str, info: bool = False) -> str:
  {{ log("Running some_macro: " ~ arg1 ~ ", " ~ arg2) }}
  {% endmacro %}"
  """
+
+ if not isinstance(msg, str):
+ msg = str(msg)
+
  if info:
  fire_event(MacroEventInfo(msg=msg))
  else: