Issue #9566: cast unsigned int to Py_ssize_t in md5 and sha1 modules

Fix a compiler warning on Windows 64 bits.

Modules/md5module.c

@@ -243,7 +243,7 @@ void md5_process(struct md5_state *md5,
            in             += MD5_BLOCKSIZE;
            inlen          -= MD5_BLOCKSIZE;
         } else {
-           n = MIN(inlen, (MD5_BLOCKSIZE - md5->curlen));
+           n = MIN(inlen, (Py_ssize_t)(MD5_BLOCKSIZE - md5->curlen));
            memcpy(md5->buf + md5->curlen, in, (size_t)n);
            md5->curlen    += n;
            in             += n;

Modules/sha1module.c

@@ -218,7 +218,7 @@ void sha1_process(struct sha1_state *sha1,
            in             += SHA1_BLOCKSIZE;
            inlen          -= SHA1_BLOCKSIZE;
         } else {
-           n = MIN(inlen, (SHA1_BLOCKSIZE - sha1->curlen));
+           n = MIN(inlen, (Py_ssize_t)(SHA1_BLOCKSIZE - sha1->curlen));
            memcpy(sha1->buf + sha1->curlen, in, (size_t)n);
            sha1->curlen   += n;
            in             += n;