/usr/lib/R/site-library/ShortRead/unitTests/cases/solexa.fastq is in r-bioc-shortread 1.36.0-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 | @solexa ASCII 59-126; 59-104 realistic
GCGCGGATCTTTAGCATTGTAGTACCGGACATAACAACAATTTTGCC
+solexa ASCII 59-126; 59-104 realistic
;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefgh
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