Backport PR #12909 on branch maint/1.8 (Fix GDF NumPy >= 2) (#12915)

Co-authored-by: Clemens Brunner <clemens.brunner@gmail.com>

Author: meeseeksmachine

doc/changes/devel/12909.bugfix.rst

@@ -0,0 +1 @@
+Fix bug in :func:`mne.io.read_raw_gdf` when NumPy >= 2 is used, by `Clemens Brunner`_.

mne/io/edf/edf.py

@@ -1442,7 +1442,7 @@ def _read_gdf_header(fname, exclude, include=None):
                     ne = np.fromfile(fid, UINT8, 3)
                     n_events = ne[0]
                     for i in range(1, len(ne)):
-                        n_events = n_events + ne[i] * 2 ** (i * 8)
+                        n_events = n_events + int(ne[i]) * 2 ** (i * 8)
                     event_sr = np.fromfile(fid, FLOAT32, 1)[0]
 
                 pos = np.fromfile(fid, UINT32, n_events) - 1  # 1-based inds