infra: add UV_FROZEN to makefiles (#29642)

These are set in Github workflows, but forgot to add them to most
makefiles for convenience when developing locally.

`uv run` will automatically sync the lock file. Because many of our
development dependencies are local installs, it will pick up version
changes and update the lock file. Passing `--frozen` or setting this
environment variable disables the behavior.

libs/partners/groq/Makefile

@@ -3,6 +3,9 @@
 # Default target executed when no arguments are given to make.
 all: help
 
+.EXPORT_ALL_VARIABLES:
+UV_FROZEN = true
+
 # Define a variable for the test file path.
 TEST_FILE ?= tests/unit_tests/