[ML] Fix CI analytics steps failing with exit code 127 (#3000)

The python:3-slim image lacks curl and git, which the Buildkite
agent environment hook requires. This caused the analyze_build_timings,
ingest_build_timings, and check_build_regression steps to fail with
exit code 127 ("command not found").

Made-with: Cursor

Author: edsavage

.buildkite/pipelines/analyze_build_timings.yml.sh

@@ -22,5 +22,5 @@ steps:
     allow_dependency_failure: true
     soft_fail: true
     agents:
-      image: "python:3-slim"
+      image: "python:3"
 EOL

.buildkite/pipelines/check_build_regression.yml.sh

@@ -22,5 +22,5 @@ steps:
     allow_dependency_failure: true
     soft_fail: true
     agents:
-      image: "python:3-slim"
+      image: "python:3"
 EOL

.buildkite/pipelines/ingest_build_timings.yml.sh

@@ -23,7 +23,7 @@ steps:
     allow_dependency_failure: true
     soft_fail: true
     agents:
-      image: "python:3-slim"
+      image: "python:3"
     env:
       BUILDKITE_API_READ_TOKEN: ""
 EOL