Fix missing f-prefix in exponential histogram max_size error messages

[Eason09053360]

Description

The two ValueError messages in _ExponentialBucketHistogramAggregation are built by concatenating an f-string with a plain string literal, and the continuation lines were missing the f prefix. As a result, users saw the literal placeholder text instead of the actual limits:

Buckets max size 1 is smaller than minimum max size {self._min_max_size}

This PR adds the missing f prefix to both continuation strings, so the messages now render the actual values:

Buckets max size 1 is smaller than minimum max size 2
Buckets max size 20000 is larger than maximum max size 16384

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Manually triggered both error paths and verified the rendered messages:

from opentelemetry.sdk.metrics._internal.aggregation import _ExponentialBucketHistogramAggregation
from unittest.mock import Mock

for size in (1, 20000):
    try:
        _ExponentialBucketHistogramAggregation(Mock(), Mock(), 0, 0, max_size=size)
    except ValueError as e:
        print(e)

Existing unit tests for _ExponentialBucketHistogramAggregation still pass.

Does This PR Require a Contrib Repo Change?

• No.

Checklist:

• Followed the style guidelines of this project
• Changelogs have been updated

[herin049]

Please add a changelog fragement.

[Eason09053360]

Please add a changelog fragement.

applied thanks :)