Add eScience sponsor logo (#757)

Author: stefanv

content/summits/developer/2025/_index.md

@@ -32,6 +32,16 @@ height = 120
 {{< /image >}}
 '''
 
+[[item]]
+body = '''
+{{< image >}}
+lightsrc = 'eScience-logo.svg'
+darksrc = 'eScience-logo-dark.svg'
+alt = 'eScience Institute logo'
+height = 120
+{{< /image >}}
+'''
+
 [[item]]
 body = '''
 {{< image >}}