Fix build with poppler-26.01.0.

See also upstream PR https://github.com/OSGeo/gdal/pull/13664

Index: frmts/pdf/pdfobject.cpp
--- frmts/pdf/pdfobject.cpp.orig
+++ frmts/pdf/pdfobject.cpp
@@ -1411,7 +1411,7 @@ int64_t GDALPDFStreamPoppler::GetLength(int64_t nMaxSi
 
 #if POPPLER_MAJOR_VERSION > 25 ||                                              \
     (POPPLER_MAJOR_VERSION == 25 && POPPLER_MINOR_VERSION >= 2)
-    if (!m_poStream->reset())
+    if (!m_poStream->rewind())
         return 0;
 #else
     m_poStream->reset();
@@ -1490,7 +1490,7 @@ int64_t GDALPDFStreamPoppler::GetRawLength()
     auto undecodeStream = m_poStream->getUndecodedStream();
 #if POPPLER_MAJOR_VERSION > 25 ||                                              \
     (POPPLER_MAJOR_VERSION == 25 && POPPLER_MINOR_VERSION >= 2)
-    if (!undecodeStream->reset())
+    if (!undecodeStream->rewind())
         return 0;
 #else
     undecodeStream->reset();
