a single float8 constant was parsered to different float value in a single query

**Describe the problem**

Please describe the issue you observed, and any steps we can take to reproduce it:

The last `EXECUTE` statement returns two different float values, but the equivalent `SELECT` query only returns one row. if I remove the `GROUP BY`, then the `EXECUTE` statement returns one row

```
CREATE TABLE t1 (c0 FLOAT UNIQUE , c1 FLOAT);
INSERT INTO t1 (c1) VALUES(0.22602838822570093);
UPSERT INTO t1 (rowid, c1) VALUES(1283693985, 0.116859849449506);
INSERT INTO t1 (c1) VALUES(0.6838727571067713), (0.20784120532437889);
UPSERT INTO t1 (c1) VALUES(0.5282973490828922);
INSERT INTO t1 (c1) VALUES(0.20784120532437889);
INSERT INTO t1 (c1, c0, rowid) VALUES(0.9830883959498111, 0.9983111979135002, -1085919062);
SELECT DISTINCT AVG(0.5807336433647674) FROM t1 GROUP BY t1.c0;
PREPARE prepare_query (float8) AS SELECT DISTINCT AVG($1) FROM t1 GROUP BY t1.c0;
EXECUTE prepare_query(0.5807336433647674);
```

**To Reproduce**

What did you do? Describe in your own words.

this is the output:

```
> SELECT DISTINCT AVG(0.5807336433647674) FROM t1 GROUP BY t1.c0;
avg
--------------------------
0.58073364336476740000
(1 row)

Time: 0ms

> PREPARE prepare_query (float8) AS SELECT DISTINCT AVG($1) FROM t1 GROUP BY t1.c0;
PREPARE

Time: 0ms

> EXECUTE prepare_query(0.5807336433647674);
avg
----------------------
0.5807336433647673
0.5807336433647674
(2 rows)

Time: 0ms
```

**Expected behavior**
A clear and concise description of what you expected to happen.

the `EXECUTE` statement only returns one row.

**Additional data / screenshots**
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of the supporting tables.

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**Environment:**
- CockroachDB version [25.2.2]
- Server OS: [Linux]
- Client app [`cockroach sql`, JDBC]

**Additional context**
What was the impact?

Add any other context about the problem here.

Jira issue: CRDB-52216