docs(concepts): remove outdated refs to SQLAlchemy

docs/concepts/composable-ecosystem.qmd

@@ -46,7 +46,6 @@ About pandas'"](https://wesmckinney.com/blog/apache-arrow-pandas-internals/).
 
 Ibis started as a pandas-like API for Apache Impala, but has since expanded to
 support many backends. It currently leverages open-source projects like
-[SQLAlchemy](https://github.com/sqlalchemy/sqlalchemy) and
 [SQLGlot](https://github.com/tobymao/sqlglot) to work with many backends. While
 these projects are great, they rely on backend-specific SQL that does not
 constitute a standard. Going forward, we expect ADBC and Substrait to be the

docs/concepts/internals.qmd

@@ -125,11 +125,10 @@ The next major component of Ibis is the compilers.
 
 The first few versions of Ibis directly generated strings, but the compiler
 infrastructure was generalized to support compilation of
-[SQLAlchemy](https://docs.sqlalchemy.org/en/latest/tutorial/index.html#unified-tutorial) based
-expressions.
+[SQLGlot](https://sqlglot.com/)-based expressions.
 
 The compiler works by translating the different pieces of SQL expression into a
-string or SQLAlchemy expression.
+string or SQLGlot expression.
 
 The main pieces of a `SELECT` statement are:
 

gen_redirects.py

@@ -56,7 +56,6 @@
     "/api/backends/base/": "/reference/backends/base/",
     "/api/backends/pandas/": "/reference/backends/pandas/",
     "/api/backends/sql/": "/reference/backends/sql/",
-    "/api/backends/sqlalchemy/": "/reference/backends/sqlalchemy/",
     "/api/config/": "/reference/config/",
     "/api/datatypes/": "/reference/datatypes/",
     "/api/expressions/": "/reference/expressions/",
@@ -143,7 +142,9 @@
     "/ibis-for-dplyr-users/": "/tutorial/ibis-for-dplyr-users/",
     "/ibis-for-pandas-users/": "/tutorial/ibis-for-pandas-users/",
     "/ibis-for-sql-programmers/": "/tutorial/ibis-for-sql-users/",
+    "/reference/backends/": "/backends/",
     "/reference/backends/pandas/": "/backends/pandas/",
+    "/reference/config/": "/how-to/configure/basics",
     "/reference/expressions/": "/reference/",
     "/reference/expressions/collections/": "/reference/expression-collections",
     "/reference/expressions/generic/": "/reference/expression-generic",
@@ -172,7 +173,6 @@
     # TODO: "/how_to/memtable_join/"
     # TODO: "/reference/backends/base/"
     # TODO: "/reference/backends/sql/"
-    # TODO: "/reference/backends/sqlalchemy/"
 }
 
 # Fill in templates