sagemathgh-41025: set full path to sage-num-threads.py in sage-env

fixes sagemath#40889
Apparently we no longer put SAGE_ROOT/src/bin/ in PATH

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URL: sagemath#41025
Reported by: Dima Pasechnik
Reviewer(s): Max Alekseyev, user202729

Author: Release Manager

build/pkgs/configure/checksums.ini

@@ -1,3 +1,3 @@
 tarball=configure-VERSION.tar.gz
-sha1=3e57fc7934730083eab3cabb135a66b971a088b4
-sha256=eedf8f844117ad48408e49218128108f950efd7d31b4c62e1e4d5c17fba9265b
+sha1=22b3e6d593dea478344c3bde0f9e0e7a245ec048
+sha256=7e0c7b79ade800e46e47f1dd528ab5bc9b892ecb881a8daf5ebea75eb5e8a837

build/pkgs/configure/package-version.txt

@@ -1 +1 @@
-a9c77acf2428df6899d91b1a943b768a22dafed5
+a4ee1626d845158adbb15f5ac48c6ba08537324c

src/bin/sage-env

@@ -580,7 +580,7 @@ case "$SAGE_NUM_THREADS,$SAGE_NUM_THREADS_PARALLEL" in
         # First, figure out the right values for SAGE_NUM_THREADS (default
         # number of threads) and SAGE_NUM_THREADS_PARALLEL (default number of
         # threads when parallel execution is asked explicitly).
-        sage_num_threads_array=$(sage-num-threads.py 2>/dev/null || echo 1 2 1)
+        sage_num_threads_array=$("$(dirname "$0")"/sage-num-threads.py 2>/dev/null || echo 1 2 1)
         sage_num_threads_array="${sage_num_threads_array% *}" # strip third item
         SAGE_NUM_THREADS="${sage_num_threads_array% *}" # keep first item
         SAGE_NUM_THREADS_PARALLEL="${sage_num_threads_array#* }" # keep second item