join_where ColumnNotFound error for LazyFrame query

[cmdlineluser]

Checks

• I have checked that this issue has not already been reported.
• I have confirmed this bug exists on the latest version of Polars.

Reproducible example

import polars as pl

lf = pl.LazyFrame({"a": [1, 2], "b": [3, 4]}).with_row_index()

(lf.join_where(lf,
      pl.col.index < pl.col.index_right,
      pl.col.index + pl.col.a > pl.col.a_right
   )
   .group_by(pl.col.index)
   .agg(pl.col.index_right)
   .collect()
)

# ColumnNotFoundError: "a" not found

Log output

No response

Issue description

The query runs with projection_pushdown disabled.

   .collect(projection_pushdown=False)
)
# shape: (0, 2)
# ┌───────┬─────────────┐
# │ index ┆ index_right │
# │ ---   ┆ ---         │
# │ u32   ┆ list[u32]   │
# ╞═══════╪═════════════╡
# └───────┴─────────────┘

If the column is included in the .agg() - the error is also not present.

Expected behavior

No error.

Installed versions

--------Version info---------
Polars:               1.8.2
Index type:           UInt32
Platform:             macOS-13.6.1-arm64-arm-64bit
Python:               3.12.2 (main, Feb  6 2024, 20:19:44) [Clang 15.0.0 (clang-1500.1.0.2.5)]

----Optional dependencies----
adbc_driver_manager:  <not installed>
cloudpickle:          <not installed>
connectorx:           <not installed>
deltalake:            <not installed>
fastexcel:            <not installed>
fsspec:               <not installed>
gevent:               <not installed>
great_tables:         <not installed>
hvplot:               <not installed>
matplotlib:           <not installed>
nest_asyncio:         <not installed>
numpy:                1.26.4
openpyxl:             <not installed>
pandas:               2.2.1
pyarrow:              15.0.2
pydantic:             <not installed>
pyiceberg:            <not installed>
sqlalchemy:           <not installed>
torch:                <not installed>
xlsx2csv:             <not installed>
xlsxwriter:           <not installed>

[ritchie46]

@nameexhaustion can you take a look?